This patch addresses kernel bug 56661. BIOS reports an incorrect
backlight value, causing the driver to switch off the backlight
completely during startup. This patch ignores the incorrect value from
BIOS.
References: https://bugzilla.kernel.org/show_bug.cgi?id=56661 Signed-off-by: Ash Willis <ashwillis@programmer.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On HP m4 lapops, BIOS reports minimum backlight on boot and
causes backlight to dim completely. This ignores the initial backlight
values and set to max brightness.
References: https://bugs.launchpad.net/bugs/1184501 Signed-off-by: Alex Hung <alex.hung@canonical.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 4b31e774 (Always set P-state on initialization) fixed bug
#4634 and caused the driver to always set the target P-State at
least once since the initial P-State may not be the desired one.
Commit 5a1c0228 (cpufreq: Avoid calling cpufreq driver's target()
routine if target_freq == policy->cur) caused a regression in
this behavior.
This fixes the regression by setting policy->cur based on the CPU's
target frequency rather than the CPU's current reported frequency
(which may be different). This means that the P-State will be set
initially if the CPU's target frequency is different from the
governor's target frequency.
This fixes an issue where setting the default governor to
performance wouldn't correctly enable turbo mode on all cores.
Signed-off-by: Ross Lagerwall <rosslagerwall@gmail.com> Reviewed-by: Len Brown <len.brown@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix regression introduced by commit 0eafe4de1a ("USB: serial: mos7840:
add support for MCS7810 devices") which used stack-allocated buffers for
control messages.
Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch reverts commit 3e619d04159be54b3daa0b7036b0ce9e067f4b5d
(USB: EHCI: fix bug in scheduling periodic split transfers). The
commit was valid -- it fixed a real bug -- but the periodic scheduler
in ehci-hcd is in such bad shape (especially the part that handles
split transactions) that fixing one bug is very likely to cause
another to surface. That's what happened in this case; the result was
choppy and noisy playback on certain 24-bit audio devices.
The only real fix will be to rewrite this entire section of code. My
next project...
This fixes https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1136110.
Thanks to Tim Richardson for extra testing and feedback, and to Joseph
Salisbury and Tyson Tan for tracking down the original source of the
problem.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Joseph Salisbury <joseph.salisbury@canonical.com> CC: Tim Richardson <tim@tim-richardson.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When configuring the port (e.g. set_termios) the port minor number
rather than the port number was used in the request (and they only
coincide for minor number 0).
Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The patch adds a new HIDCOM device and does not affect other devices
driven by the cypress_M8 module. Changes are:
- add VendorID ProductID to device tables
- skip unstable speed check because FRWD uses 115200bps
- skip reset at probe which is an issue workaround for this
particular device.
Signed-off-by: Robert Butora <robert.butora.fi@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix regression introduced by commit 214916f2e ("USB: visor: reimplement
using generic framework") which broke initialisation of Treo/Kyocera
devices that re-mapped bulk-in endpoints.
Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB audio driver spews an error message when probing Logitech HD
webcam c270:
ALSA mixer.c:1300 usb_audio: Warning! Unlikely big volume range (=6144), cval->res is probably wrong.
ALSA mixer.c:1304 usb_audio: [5] FU [Mic Capture Volume] ch = 1, val = 1536/7680/1
Obviously the device needs a fixed volume resolution (cval->res = 384)
like other Logitech devices.
Commit 927c9423dd5f2d1c0b93d5e694ab84b4a5559713 (ALSA: usb-audio: add
Edirol UM-3G support) used a wrong quirk type, which would make the
driver refuse to attach with the error message "MIDIStreaming interface
descriptor not found".
8e8a551 usb: musb: host: Handle highmem in PIO mode
when a URB is being handled it may happen that the static use_sg flag
was set by a previous URB with buffer in highmem. This leads to error
in handling the present URB.
f9a37be0f0 ("x86: Use PCI setup data") added support for using PCI ROM
images from setup_data. This used phys_to_virt(), which is not valid for
highmem addresses, and can cause a crash when booting a 32-bit kernel via
the EFI boot stub.
pcibios_add_device() assumes that the physical addresses stored in
setup_data are accessible via the direct kernel mapping, and that calling
phys_to_virt() is valid. This isn't guaranteed to be true on x86 where the
direct mapping range is much smaller than on x86-64.
Calling phys_to_virt() on a highmem address results in the following:
Some xHCI hosts contain a "redriver" from TI that silently drops port
status connect changes if the port slips into Compliance Mode. If the
port slips into compliance mode while the host is in D0, there will not
be a port status change event. If the port slips into compliance mode
while the host is in D3, the host will not send a PME. This includes
when the system is suspended (S3) or hibernated (S4).
If this happens when the system is in S3/S4, there is nothing software
can do. Other port status change events that would normally cause the
host to wake the system from S3/S4 may also be lost. This includes
remote wakeup, disconnects and connects on other ports, and overrcurrent
events. A decision was made to _NOT_ disable system suspend/hibernate
on these systems, since users are unlikely to enable wakeup from S3/S4
for the xHCI host.
Software can deal with this issue when the system is in S0. A work
around was put in to poll the port status registers for Compliance Mode.
The xHCI driver will continue to poll the registers while the host is
runtime suspended. Unfortunately, that means we can't allow the PCI
device to go into D3cold, because power will be removed from the host,
and the config space will read as all Fs.
Disable D3cold in the xHCI PCI runtime suspend function.
This patch should be backported to kernels as old as 3.2, that
contain the commit 71c731a296f1b08a3724bd1b514b64f1bda87a23 "usb: host:
xhci: Fix Compliance Mode on SN65LVPE502CP Hardware"
If for whatever reason we fall into fail path in xhci_mem_init()
before bw table gets initialized we may access the uninitialized lists
in xhci_mem_cleanup().
Check for bw table before traversing lists in cleanup routine.
This patch should be backported to kernels as old as 3.2, that contain
the commit 839c817ce67178ca3c7c7ad534c571bba1e69ebe "xhci: Store
information about roothubs and TTs."
Reported-by: Sergey Dyasly <dserrg@gmail.com> Tested-by: Sergey Dyasly <dserrg@gmail.com> Signed-off-by: Vladimir Murzin <murzin.v@gmail.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is possible that we fail on xhci_mem_init, just before doing
the INIT_LIST_HEAD, and calling xhci_mem_cleanup.
Problem is that, the list_for_each_entry_safe macro, assumes
list heads are initialized (not NULL), and dereferences their 'next'
pointer, causing a kernel panic if this is not yet initialized.
Let's protect from that by moving inits to the beginning.
Commit 71c731a2 (usb: host: xhci: Fix Compliance Mode on SN65LVPE502CP
Hardware) was a workaround for systems using the SN65LVPE502CP,
controller, but it introduced a bug in resume from hibernate.
The fix created a timer, comp_mode_recovery_timer, which is deleted from
a timer list when xhci_suspend() is called. However, the hibernate image,
including the timer list containing the comp_mode_recovery_timer, had
already been saved before the timer was deleted.
Upon resume from hibernate, the list containing the comp_mode_recovery_timer
is restored from the image saved to disk, and xhci_resume(), assuming that
the timer had been deleted by xhci_suspend(), makes a call to
compliance_mode_recoery_timer_init(), which creates a new instance of the
comp_mode_recovery_timer and attempts to place it into the same list in which
it is already active, thus corrupting the list during the list_add() call.
At this point, a call trace is emitted indicating the list corruption.
Soon afterward, the system locks up, the watchdog times out, and the
ensuing NMI crashes the system.
The problem did not occur when resuming from suspend. In suspend, the
image in RAM remains exactly as it was when xhci_suspend() deleted the
comp_mode_recovery_timer, so there is no problem when xhci_resume()
creates a new instance of this timer and places it in the still empty
list.
This patch avoids the problem by deleting the timer in xhci_resume()
when resuming from hibernate. Now xhci_resume() can safely make the
call to create a new instance of this timer, whether returning from
suspend or hibernate.
Thanks to Alan Stern for his help with understanding the problem.
[Sarah reworked this patch to cover the case where the xHCI restore
register operation fails, and (temp & STS_SRE) is true (and we re-init
the host, including re-init for the compliance mode), but hibernate is
false. The original patch would have caused list corruption in this
case.]
This patch should be backported to kernels as old as 3.2, that
contain the commit 71c731a296f1b08a3724bd1b514b64f1bda87a23 "usb: host:
xhci: Fix Compliance Mode on SN65LVPE502CP Hardware"
Signed-off-by: Tony Camuso <tcamuso@redhat.com> Tested-by: Tony Camuso <tcamuso@redhat.com> Acked-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the glue layer is removed first (core layer later),
it deletes the phy device first, then the core device.
But at core's removal, it still uses PHY's resources, it may
cause kernel's oops. It is much like the problem
Paul Zimmerman reported at:
http://marc.info/?l=linux-usb&m=136547502011472&w=2.
Besides, it is reasonable the PHY is deleted at last as
the controller is the PHY's user.
Signed-off-by: Peter Chen <peter.chen@freescale.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Per some ZTE Linux drivers I found for the AC2716, the following patch
moves most ZTE CDMA devices from option to zte_ev. The blacklist stuff
that option does is not required with zte_ev, because it doesn't
implement any of the send_setup hooks which the blacklist suppressed.
I did not move the 2718 over because I could not find any ZTE Linux
drivers for that device, nor even any Windows drivers.
Signed-off-by: Dan Williams <dcbw@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The fatal_skb_slots is the threshold to determine whether a packet is
malicious.
XEN_NETBK_LEGACY_SLOTS_MAX is the maximum slots a valid packet can have at
this point. It is defined to be XEN_NETIF_NR_SLOTS_MIN because that's
guaranteed to be supported by all backends.
Suggested-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Johannes Berg [Thu, 23 May 2013 20:24:11 +0000 (22:24 +0200)]
mac80211_hwsim: remove P2P_DEVICE support
Unfortunately, advertising P2P_DEVICE support was a little
premature, a number of issues came up in testing and have
been fixed for 3.10. Rather than try to backport all the
different fixes, disable P2P_DEVICE support in the drivers
using it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Johannes Berg [Thu, 23 May 2013 20:24:31 +0000 (22:24 +0200)]
iwlwifi: mvm: remove P2P_DEVICE support
Unfortunately, advertising P2P_DEVICE support was a little
premature, a number of issues came up in testing and have
been fixed for 3.10. Rather than try to backport all the
different fixes, disable P2P_DEVICE support in the drivers
using it. For iwlmvm that implies disabling P2P completely
as it can't support P2P operation w/o P2P Device.
Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The maximum packet including header that can be handled by netfront / netback
wire format is 65535. Reduce gso_max_size accordingly.
Drop skb and print warning when skb->len > 65535. This can 1) save the effort
to send malformed packet to netback, 2) help spotting misconfiguration of
netfront in the future.
Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tune xen_netbk_count_requests to not touch working array beyond limit, so that
we can make working array size constant.
Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tracking down from the caller, first_idx is always equal to vif->tx.req_cons.
Remove it to avoid confusion.
Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some frontend drivers are sending packets > 64 KiB in length. This length
overflows the length field in the first slot making the following slots have
an invalid length.
Turn this error back into a non-fatal error by dropping the packet. To avoid
having the following slots having fatal errors, consume all slots in the
packet.
This does not reopen the security hole in XSA-39 as if the packet as an
invalid number of slots it will still hit fatal error case.
Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch tries to coalesce tx requests when constructing grant copy
structures. It enables netback to deal with situation when frontend's
MAX_SKB_FRAGS is larger than backend's MAX_SKB_FRAGS.
With the help of coalescing, this patch tries to address two regressions
avoid reopening the security hole in XSA-39.
Regression 1. The reduction of the number of supported ring entries (slots)
per packet (from 18 to 17). This regression has been around for some time but
remains unnoticed until XSA-39 security fix. This is fixed by coalescing
slots.
Regression 2. The XSA-39 security fix turning "too many frags" errors from
just dropping the packet to a fatal error and disabling the VIF. This is fixed
by coalescing slots (handling 18 slots when backend's MAX_SKB_FRAGS is 17)
which rules out false positive (using 18 slots is legit) and dropping packets
using 19 to `max_skb_slots` slots.
To avoid reopening security hole in XSA-39, frontend sending packet using more
than max_skb_slots is considered malicious.
The behavior of netback for packet is thus:
1-18 slots: valid
19-max_skb_slots slots: drop and respond with an error
max_skb_slots+ slots: fatal error
max_skb_slots is configurable by admin, default value is 20.
Also change variable name from "frags" to "slots" in netbk_count_requests.
Please note that RX path still has dependency on MAX_SKB_FRAGS. This will be
fixed with separate patch.
Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit a99d76f (leds: leds-gpio: use gpio_request_one)
and commit 2d7c22f (leds: leds-gpio: set devm_gpio_request_one()
flags param correctly) which was a fix of the first one.
The conversion to devm_gpio_request in commit e3b1d44c (leds:
leds-gpio: use devm_gpio_request_one) is not reverted.
The problem is that gpio_cansleep() and gpio_get_value_cansleep()
calls can crash if the gpio is not first reserved. Incidentally this
same bug existed earlier and was fixed similarly in commit d95cbe61
(leds: Fix potential leds-gpio oops). But the OOPS is real. It happens
when GPIOs are provided by module which is not yet loaded.
So this fixes the following BUG during my ALIX boot (3.9.2-vanilla):
This patch fixes a bug where FILEIO was incorrectly reporting the number
of logical blocks (+ 1) when using non struct block_device export mode.
It changes fd_get_blocks() to follow all other backend ->get_blocks() cases,
and reduces the calculated dev_size by one dev->dev_attrib.block_size
number of bytes, and also fixes initial fd_block_size assignment at
fd_configure_device() time introduced in commit 0fd97ccf4.
Switch back to pre commit 1c7b13fe652 list splicing logic for active I/O
shutdown with tcm_qla2xxx + ib_srpt fabrics.
The original commit was done under the incorrect assumption that it's safe to
walk se_sess->sess_cmd_list unprotected in target_wait_for_sess_cmds() after
sess->sess_tearing_down = 1 has been set by target_sess_cmd_list_set_waiting()
during session shutdown.
So instead of adding sess->sess_cmd_lock protection around sess->sess_cmd_list
during target_wait_for_sess_cmds(), switch back to sess->sess_wait_list to
allow wait_for_completion() + TFO->release_cmd() to occur without having to
walk ->sess_cmd_list after the list_splice.
Also add a check to exit if target_sess_cmd_list_set_waiting() has already
been called, and add a WARN_ON to check for any fabric bug where new se_cmds
are added to sess->sess_cmd_list after sess->sess_tearing_down = 1 has already
been set.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Joern Engel <joern@logfs.org> Cc: Roland Dreier <roland@kernel.org> Signed-off-by: Lingzhu Xiang <lxiang@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix bug introduced by commit 4582a4ab2a "FUSE: Adapt readdirplus to application
usage patterns".
We need to check for a positive dentry; negative dentries are not added by
readdirplus. Secondly we need to advise the use of readdirplus on the *parent*,
otherwise the whole thing is useless. Thirdly all this is only relevant if
"readdirplus_auto" mode is selected by the filesystem.
We advise the use of readdirplus only if the dentry was still valid. If we had
to redo the lookup then there was no use in doing the -plus version.
McASP serial audio engine needs different rotation values on TX and RX
channels. Commit dde109fb462 ("ASoC: McASP: Fix data rotation for
playback. Enables 24bit audio playback") changed the calculation to fix
the playback format, but broke the capture stream by doing it for both
TXFMT and RXFMT.
Signed-off-by: Daniel Mack <zonque@gmail.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Lingzhu Xiang <lxiang@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 819a087316a6 ("IB/iser: Avoid error prints on EAGAIN
registration failures") not only eliminated the error print on that
case, but rather also modified the code such that it doesn't return
any error to upper layers. As a result a wrong mapping was used. Fix
this to correctly return the error in that case.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Unlike Kvaser Leaf light devices, some other Kvaser devices (like USBcan
Pro, USBcan R) receive CAN messages in CMD_LOG_MESSAGE frames. This
patch adds support for it.
Signed-off-by: Jonas Peterson <jonas.peterson@gmail.com> Signed-off-by: Olivier Sobrie <olivier@sobrie.be> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 091f0ea30074bc43f9250961b3247af713024bc6 "tg3: Add New 5719 Read
DMA workaround" added a workaround for TX DMA stall on the 5719. This
workaround needs to be applied to the 5720 as well.
Reported-by: Roland Dreier <roland@purestorage.com> Tested-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com> Signed-off-by: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a P2P-Device is present and another virtual interface triggers
the connection work, the system crash because it tries to check
if the P2P-Device's netdev (which doesn't exist) is up. Skip any
wdevs that have no netdev to fix this.
Without this command, the firmware will filter out all the
multicast frames. Let them all in as for now. Later we will
want to optimize this to save power.
I tried to avoid to send zeroed LQ cmd, but I made a (very)
stupid mistake in the memcmp.
Since this patch has been ported to stable, the fix should
go to stable too.
This fixes https://bugzilla.kernel.org/show_bug.cgi?id=58341
Reported-by: Hinnerk van Bruinehsen <h.v.bruinehsen@fu-berlin.de> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since Eric's commit efe117ab8 ("Speedup ieee80211_remove_interfaces")
there's a bug in mac80211 when it unregisters with AP_VLAN interfaces
up. If the AP_VLAN interface was registered after the AP it belongs
to (which is the typical case) and then we get into this code path,
unregister_netdevice_many() will crash because it isn't prepared to
deal with interfaces being closed in the middle of it. Exactly this
happens though, because we iterate the list, find the AP master this
AP_VLAN belongs to and dev_close() the dependent VLANs. After this,
unregister_netdevice_many() won't pick up the fact that the AP_VLAN
is already down and will do it again, causing a crash.
Signed-off-by: Johannes Berg <johannes.berg@intel.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We send direct probe to broadcast address, as some APs do not respond to
unicast PROBE frames when unassociated. Broadcast frames are not acked,
so we can not use that for trigger MLME state machine, but we need to
use old timeout mechanism.
This fixes authentication timed out like below:
[ 1024.671974] wlan6: authenticate with 54:e6:fc:98:63:fe
[ 1024.694125] wlan6: direct probe to 54:e6:fc:98:63:fe (try 1/3)
[ 1024.695450] wlan6: direct probe to 54:e6:fc:98:63:fe (try 2/3)
[ 1024.700586] wlan6: send auth to 54:e6:fc:98:63:fe (try 3/3)
[ 1024.701441] wlan6: authentication with 54:e6:fc:98:63:fe timed out
With fix, we have:
[ 4524.198978] wlan6: authenticate with 54:e6:fc:98:63:fe
[ 4524.220692] wlan6: direct probe to 54:e6:fc:98:63:fe (try 1/3)
[ 4524.421784] wlan6: send auth to 54:e6:fc:98:63:fe (try 2/3)
[ 4524.423272] wlan6: authenticated
[ 4524.423811] wlan6: associate with 54:e6:fc:98:63:fe (try 1/3)
[ 4524.427492] wlan6: RX AssocResp from 54:e6:fc:98:63:fe (capab=0x431 status=0 aid=1)
The falcon is present, but the rest of the copy engine doesn't appear to
be... PUNITS doesn't report disabled (maybe the bits for the copy engines
got added later?), so we end up trying to use a non-functional CE1, and
bust all sorts of things.. Most notably, suspend/resume..
Like on UL30VT, the ACPI video driver can't control backlight correctly on
Asus UL30A. Vendor driver (asus-laptop) can work. This patch is to
add "Asus UL30A" to ACPI video detect blacklist in order to use
asus-laptop for video control on the "Asus UL30A" rather than ACPI
video driver.
Signed-off-by: Bastian Triller <bastian.triller@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, drivers/acpi/device_pm.c depends on CONFIG_PM and all of
the functions defined in there are replaced with static inline stubs
if that option is unset. However, CONFIG_PM means, roughly, "runtime
PM or suspend/hibernation support" and some of those functions are
useful regardless of that. For example, they are used by the ACPI
fan driver for controlling fans and acpi_device_set_power() is called
during device removal. Moreover, device initialization may depend on
setting device power states properly.
For these reasons, make the routines manipulating ACPI device power
states defined in drivers/acpi/device_pm.c available for CONFIG_PM
unset too.
Reported-by: Zhang Rui <rui.zhang@intel.com> Reported-and-tested-by: Michel Lespinasse <walken@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Work around an IOMMU hardware bug where clearing the
EVT_INT or PPR_INT bit in the status register may race with
the hardware trying to set it again. When not handled the
bit might not be cleared and we lose all future event or ppr
interrupts.
Current driver does not clear the IOMMU event log interrupt bit
in the IOMMU status register after processing an interrupt.
This causes the IOMMU hardware to generate event log interrupt only once.
This has been observed in both IOMMU v1 and V2 hardware.
This patch clears the bit by writing 1 to bit 1 of the IOMMU
status register (MMIO Offset 2020h)
Move the counter for non-AMPDU frames to mvm. It is needed
for the drain flow which happens once the ieee80211_sta has
been freed, so keeping it in iwl_mvm_sta which is embed into
ieee80211_sta is not a good idea.
Also, since its purpose it to remove the STA in the fw only
after all the frames for this station have exited the shared
Tx queues, we need to decrement it in the reclaim flow. This
flow can happen after ieee80211_sta has been removed, which
means that we have no iwl_mvm_sta there. So we can't know
what is the vif type. Hence, we know audit these frames for
all the vif types.
In order to avoid spawning sta_drained_wk all the time, we
now check that we are in a flow in which draining might
happen - only when mvmsta is NULL. This is better than
previous code that would spawn sta_drained_wk all the time
in AP mode.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Reviewed-by: Ilan Peer <ilan.peer@intel.com> Reviewed-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Lingzhu Xiang <lxiang@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes races uncovered by xfstests testcase 068.
One race is the result of jfs_sync() trying to write a sync point to the
journal after it has been frozen (or possibly in the process). Since
freezing sync's the journal, there is no need to write a sync point so
we simply want to return.
The second involves jfs_write_inode() being called on a deleted inode.
It calls jfs_flush_journal which is held up by the jfs_commit thread
doing the final iput on the same deleted inode, which itself is
waiting for the I_SYNC flag to be cleared. jfs_write_inode need not
do anything when i_nlink is zero, which is the easy fix.
Reported-by: Michael L. Semon <mlsemon35@gmail.com> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After sleeping for filldir(), we check to see if the file system has
changed and research. The next_pos pointer is updated but its value
isn't pushed into the key used for the search itself. As a result,
the search returns the same item that the last cycle of the loop did
and filldir() is called multiple times with the same data.
The end result is that the buffer can contain the same name multiple
times. This can be returned to userspace or used internally in the
xattr code where it can manifest with the following warning:
jdm-20004 reiserfs_delete_xattrs: Couldn't delete all xattrs (-2)
reiserfs_for_each_xattr uses reiserfs_readdir_dentry to iterate over
the xattr names and ends up trying to unlink the same name twice. The
second attempt fails with -ENOENT and the error is returned. At some
point I'll need to add support into reiserfsck to remove the orphaned
directories left behind when this occurs.
The fix is to push the value into the key before researching.
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
reiserfs_chown_xattrs() takes the iattr struct passed into ->setattr
and uses it to iterate over all the attrs associated with a file to change
ownership of xattrs (and transfer quota associated with the xattr files).
When the setuid bit is cleared during chown, ATTR_MODE and iattr->ia_mode
are passed to all the xattrs as well. This means that the xattr directory
will have S_IFREG added to its mode bits.
This has been prevented in practice by a missing IS_PRIVATE check
in reiserfs_acl_chmod, which caused a double-lock to occur while holding
the write lock. Since the file system was completely locked up, the
writeout of the corrupted mode never happened.
This patch temporarily clears everything but ATTR_UID|ATTR_GID for the
calls to reiserfs_setattr and adds the missing IS_PRIVATE check.
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reiserfs is currently able to be deadlocked by having two NFS clients
where one has removed and recreated a file and another is accessing the
file with an open file handle.
If one client deletes and recreates a file with timing such that the
recreated file obtains the same [dirid, objectid] pair as the original
file while another client accesses the file via file handle, the create
and lookup can race and deadlock if the lookup manages to create the
in-memory inode first.
The create thread, in insert_inode_locked4, will hold the write lock
while waiting on the other inode to be unlocked. The lookup thread,
anywhere in the iget path, will release and reacquire the write lock while
it schedules. If it needs to reacquire the lock while the create thread
has it, it will never be able to make forward progress because it needs
to reacquire the lock before ultimately unlocking the inode.
This patch drops the write lock across the insert_inode_locked4 call so
that the ordering of inode_wait -> write lock is retained. Since this
would have been the case before the BKL push-down, this is safe.
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Adam Lackorzynski reported the following build failure on
!CONFIG_HOTPLUG_CPU configuration:
CC arch/powerpc/kernel/rtas.o
arch/powerpc/kernel/rtas.c: In function ‘rtas_cpu_state_change_mask’:
arch/powerpc/kernel/rtas.c:843:4: error: implicit declaration of function ‘cpu_down’ [-Werror=implicit-function-declaration]
cc1: all warnings being treated as errors
make[1]: *** [arch/powerpc/kernel/rtas.o] Error 1
make: *** [arch/powerpc/kernel] Error 2
The build fails because cpu_down() is defined only under CONFIG_HOTPLUG_CPU.
Looking further, the mobility code in pseries is one of the call-sites which
uses rtas_ibm_suspend_me(), which in turn calls rtas_cpu_state_change_mask().
And the mobility code is unconditionally compiled-in (it does not fall under
any Kconfig option). And commit 120496ac (powerpc: Bring all threads online
prior to migration/hibernation) which introduced this build regression is
critical for the proper functioning of the migration code. So it appears
that the only solution to this problem is to enable CONFIG_HOTPLUG_CPU if
SMP is enabled on PPC_PSERIES platforms. So make that change in the Kconfig.
Reported-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
regulator_enable_regmap() uses enable_reg to enable the regulator.
But enable_reg for smps10 points to SMPS10_STATUS which is a
read-only register. Fixed the same by having enable_reg
set to SMPS10_CTRL.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is encountered when booting RHEL5.9 64-bit. There is another bug
after this one that is not a simple emulation failure, but this one lets
the boot proceed a bit.
Given that srpt_release_channel_work() calls target_wait_for_sess_cmds()
to allow outstanding se_cmd_t->cmd_kref a change to complete, the call
to perform target_sess_cmd_list_set_waiting() needs to happen in
srpt_shutdown_session()
Also, this patch adds an explicit call to srpt_shutdown_session() within
srpt_drain_channel() so that target_sess_cmd_list_set_waiting() will be
called in the cases where TFO->shutdown_session() is not triggered
directly by TCM.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Joern Engel <joern@logfs.org> Cc: Roland Dreier <roland@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a key was larger than 64 bytes, as checked by iscsi_check_key(), the
error response packet, generated by iscsi_add_notunderstood_response(),
would still attempt to copy the entire key into the packet, overflowing
the structure on the heap.
Remote preauthentication kernel memory corruption was possible if a
target was configured and listening on the network.
If we are emulating an instruction inside an active user transaction that
touches memory, the kernel can't emulate it as it operates in transactional
suspend context. We need to abort these transactions and send them back to
userspace for the hardware to rollback.
We can service these if the user transaction is in suspend mode, since the
kernel will operate in the same suspend context.
This adds a check to all alignment faults and to specific instruction
emulations (only string instructions for now). If the user process is in an
active (non-suspended) transaction, we abort the transaction go back to
userspace allowing the HW to roll back the transaction and tell the user of the
failure. This also adds new tm abort cause codes to report the reason of the
persistent error to the user.
Crappy test case here http://neuling.org/devel/junkcode/aligntm.c
Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When in an active transaction that takes a signal, we need to be careful with
the stack. It's possible that the stack has moved back up after the tbegin.
The obvious case here is when the tbegin is called inside a function that
returns before a tend. In this case, the stack is part of the checkpointed
transactional memory state. If we write over this non transactionally or in
suspend, we are in trouble because if we get a tm abort, the program counter
and stack pointer will be back at the tbegin but our in memory stack won't be
valid anymore.
To avoid this, when taking a signal in an active transaction, we need to use
the stack pointer from the checkpointed state, rather than the speculated
state. This ensures that the signal context (written tm suspended) will be
written below the stack required for the rollback. The transaction is aborted
becuase of the treclaim, so any memory written between the tbegin and the
signal will be rolled back anyway.
For signals taken in non-TM or suspended mode, we use the
normal/non-checkpointed stack pointer.
Tested with 64 and 32 bit signals
Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While returning from exception handling in case of PREEMPT enabled,
_TIF_NEED_RESCHED bit is checked in TI_FLAGS (thread_info flag) of current
task. Only if this bit is set, it should continue with the process of
calling preempt_schedule_irq() to schedule highest priority task if
available.
Current code assumes that r8 contains TI_FLAGS and check this for
_TIF_NEED_RESCHED, but as r8 is modified in the code which executes before
this check, r8 no longer contains the expected TI_FLAGS information.
As a result check for comparison with _TIF_NEED_RESCHED was failing even if
NEED_RESCHED bit is set in the current thread_info flag. Due to this,
preempt_schedule_irq() and in turn scheduler was not getting called even if
highest priority task is ready for execution.
So, store temporary results in r0 instead of r8 to prevent r8 from getting
modified as subsequent code is dependent on its value.
When cgroup_next_descendant_pre() initiates a walk, it checks whether
the subtree root doesn't have any children and if not returns NULL.
Later code assumes that the subtree isn't empty. This is broken
because the subtree may become empty inbetween, which can lead to the
traversal escaping the subtree by walking to the sibling of the
subtree root.
There's no reason to have the early exit path. Remove it along with
the later assumption that the subtree isn't empty. This simplifies
the code a bit and fixes the subtle bug.
While at it, fix the comment of cgroup_for_each_descendant_pre() which
was incorrectly referring to ->css_offline() instead of
->css_online().
cgroup_create_file() calls d_instantiate(), which may decide to look
at the xattrs on the file. Smack always does this and SELinux can be
configured to do so.
But cgroup_add_file() didn't initialize xattrs before calling
cgroup_create_file(), which finally leads to dereferencing NULL
dentry->d_fsdata.
This bug has been there since cgroup xattr was introduced.
Reported-by: Ivan Bulatovic <combuster@archlinux.us> Reported-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The present code does not wait for the SCC to finish resetting itself
before trying to initialise the device. The result is that the SCC
interrupt sources become enabled (if they weren't already). This leads to
an early boot crash (unexpected interrupt) given CONFIG_EARLY_PRINTK. Fix
this by adding a delay. A successful reset disables the interrupt sources.
Also, after the reset for channel A setup, the SCC then gets a second
reset for channel B setup which leaves channel A uninitialised again. Fix
this by performing the reset only once.
libata honors DMADIR for regular commands, but not for internal commands
used (among other) during device initialisation.
This makes SATA-host-to-PATA-device bridges based on Silicon Image SiL3611
(such as "Abit Serillel 2") end up disabled when used with an ATAPI device
after a few tries.
Log output of the bridge being hot-plugged with an ATAPI drive:
[ 9631.212901] ata1: exception Emask 0x10 SAct 0x0 SErr 0x40c0000 action 0xe frozen
[ 9631.212913] ata1: irq_stat 0x00000040, connection status changed
[ 9631.212923] ata1: SError: { CommWake 10B8B DevExch }
[ 9631.212939] ata1: hard resetting link
[ 9632.104962] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 9632.106393] ata1.00: ATAPI: PIONEER DVD-RW DVR-115, 1.06, max UDMA/33
[ 9632.106407] ata1.00: applying bridge limits
[ 9632.108151] ata1.00: configured for UDMA/33
[ 9637.105303] ata1.00: qc timeout (cmd 0xa0)
[ 9637.105324] ata1.00: failed to clear UNIT ATTENTION (err_mask=0x5)
[ 9637.105335] ata1: hard resetting link
[ 9638.044599] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 9638.047878] ata1.00: configured for UDMA/33
[ 9643.044933] ata1.00: qc timeout (cmd 0xa0)
[ 9643.044953] ata1.00: failed to clear UNIT ATTENTION (err_mask=0x5)
[ 9643.044963] ata1: limiting SATA link speed to 1.5 Gbps
[ 9643.044971] ata1.00: limiting speed to UDMA/33:PIO3
[ 9643.044979] ata1: hard resetting link
[ 9643.984225] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
[ 9643.987471] ata1.00: configured for UDMA/33
[ 9648.984591] ata1.00: qc timeout (cmd 0xa0)
[ 9648.984612] ata1.00: failed to clear UNIT ATTENTION (err_mask=0x5)
[ 9648.984619] ata1.00: disabled
[ 9649.000593] ata1: hard resetting link
[ 9649.939902] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
[ 9649.955864] ata1: EH complete
With this patch, the drive enumerates correctly when libata is loaded with
atapi_dmadir=1:
The driver's interrupt handling code is too picky in deciding whether it should
handle an interrupt or not which causes completely unneeded spurious interrupts.
Thus make sata_rcar_{ata|serr}_interrupt() *void*; add ATA status register read
to sata_rcar_ata_interrupt() to clear an unexpected ATA interrupt -- it doesn't
get cleared by writing to the SATAINTSTAT register in the interrupt mode we use.
Also, in sata_rcar_ata_interrupt() we should check SATAINTSTAT register only for
enabled interrupts and we should clear only those interrupts that we have read
as active first time around, because else we have a race and risk clearing an
interrupt that can occur between read and write of the SATAINTSTAT register
and never registering it...
Iff bmdma_setup() has to stop a DMA transfer before starting a new
one, then the STOP bit in the ATAPI_CONTROL1 register will remain set
(it's only cleared when setting the START bit to 1) and then
bmdma_start() method will set both START and STOP bits simultaneously
which should abort the transfer being just started. Avoid that by
explicitly clearing the STOP bit in bmdma_start() method (in this case
it will be ignored on write).
Consider the case where we have a very short ip= string in the original
mount options, and when we chase a referral we end up with a very long
IPv6 address. Be sure to allow for that possibility when estimating the
size of the string to allocate.
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newer asics have variable numbers of crtcs. Use that
rather than the asic family to determine which crtcs
to check. This avoids checking non-existent crtcs or
missing crtcs on certain asics.
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The default register value for MASTERA_VOL is 0x00, the same as
MASTERB_VOL.
Signed-off-by: Nicolas Schichan <nschichan@freebox.fr> Acked-by: Brian Austin <brian.austin@cirrus.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As of f025adf191924e3a75ce80e130afcd2485b53bb8 "sunrpc: Properly decode
kuids and kgids in RPC_AUTH_UNIX credentials" any rpc containing a -1
(0xffff) uid or gid would fail with a badcred error.
Reported symptoms were xmbc clients failing on upgrade of the NFS
server; examination of the network trace showed them sending -1 as the
gid.
Reported-by: Julian Sikorski <belegdol@gmail.com> Tested-by: Julian Sikorski <belegdol@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The lockless RPC_IS_QUEUED() test in __rpc_execute means that we need to
be careful about ordering the calls to rpc_test_and_set_running(task) and
rpc_clear_queued(task). If we get the order wrong, then we may end up
testing the RPC_TASK_RUNNING flag after __rpc_execute() has looped
and changed the state of the rpc_task.
The s5p_csis_phy_enable/s5p_dsim_phy_enable functions are now used
directly by corresponding drivers and thus need to be exported so
the drivers can be built as modules.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rather than completely killing the kernel if we receive an esr value we
can't deal with in the el0 handlers, send the process a SIGILL and log
the esr value in the hope that we can debug it. If we receive a bad esr
from el1, we'll die() as before.
XFS has failed to kill suid/sgid bits correctly when truncating
files of non-zero size since commit c4ed4243 ("xfs: split
xfs_setattr") introduced in the 3.1 kernel. Fix it.
Fix it.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Otherwise we get a race between unload and reload of the same module:
the new module doesn't see the old one in the list, but then fails because
it can't register over the still-extant entries in sysfs:
binutils prior to 2.18 (e.g. the ones found on SLE10) don't support
assembling PEXTRD, so a macro based approach like the one for PCLMULQDQ
in the same file should be used.
This requires making the helper macros capable of recognizing 32-bit
general purpose register operands.
[ hpa: tagging for stable as it is a low risk build fix ]
Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/51A6142A02000078000D99D8@nat28.tlf.novell.com Cc: Alexander Boyko <alexander_boyko@xyratex.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Christian found v3.9 does not work with E350 with EFI is enabled.
[ 1.658832] Trying to unpack rootfs image as initramfs...
[ 1.679935] BUG: unable to handle kernel paging request at ffff88006e3fd000
[ 1.686940] IP: [<ffffffff813661df>] memset+0x1f/0xb0
[ 1.692010] PGD 1f77067 PUD 1f7a067 PMD 61420067 PTE 0
but early memtest report all memory could be accessed without problem.
early page table is set in following sequence:
[ 0.000000] init_memory_mapping: [mem 0x00000000-0x000fffff]
[ 0.000000] init_memory_mapping: [mem 0x6e600000-0x6e7fffff]
[ 0.000000] init_memory_mapping: [mem 0x6c000000-0x6e5fffff]
[ 0.000000] init_memory_mapping: [mem 0x00100000-0x6bffffff]
[ 0.000000] init_memory_mapping: [mem 0x6e800000-0x6ea07fff]
but later efi_enter_virtual_mode try set mapping again wrongly.
[ 0.010644] pid_max: default: 32768 minimum: 301
[ 0.015302] init_memory_mapping: [mem 0x640c5000-0x6e3fcfff]
that means it fails with pfn_range_is_mapped.
It turns out that we have a bug in add_range_with_merge and it does not
merge range properly when new add one fill the hole between two exsiting
ranges. In the case when [mem 0x00100000-0x6bffffff] is the hole between
[mem 0x00000000-0x000fffff] and [mem 0x6c000000-0x6e7fffff].
Fix the add_range_with_merge by calling itself recursively.