--- /dev/null
+From 9535c4757b881e06fae72a857485ad57c422b8d2 Mon Sep 17 00:00:00 2001
+From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
+Date: Tue, 21 Apr 2015 09:49:11 -0700
+Subject: drm/i915: cope with large i2c transfers
+
+From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
+
+commit 9535c4757b881e06fae72a857485ad57c422b8d2 upstream.
+
+The hardware, according to the specs, is limited to 256 byte transfers,
+and current driver has no protections in case users attempt to do larger
+transfers. The code will just stomp over status register and mayhem
+ensues.
+
+Let's split larger transfers into digestable chunks. Doing this allows
+Atmel MXT driver on Pixel 1 function properly (it hasn't since commit
+9d8dc3e529a19e427fd379118acd132520935c5d "Input: atmel_mxt_ts -
+implement T44 message handling" which tries to consume multiple
+touchscreen/touchpad reports in a single transaction).
+
+Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
+Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
+Signed-off-by: Jani Nikula <jani.nikula@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/gpu/drm/i915/i915_reg.h | 1
+ drivers/gpu/drm/i915/intel_i2c.c | 66 +++++++++++++++++++++++++++++++++------
+ 2 files changed, 57 insertions(+), 10 deletions(-)
+
+--- a/drivers/gpu/drm/i915/i915_reg.h
++++ b/drivers/gpu/drm/i915/i915_reg.h
+@@ -909,6 +909,7 @@
+ #define GMBUS_CYCLE_INDEX (2<<25)
+ #define GMBUS_CYCLE_STOP (4<<25)
+ #define GMBUS_BYTE_COUNT_SHIFT 16
++#define GMBUS_BYTE_COUNT_MAX 256U
+ #define GMBUS_SLAVE_INDEX_SHIFT 8
+ #define GMBUS_SLAVE_ADDR_SHIFT 1
+ #define GMBUS_SLAVE_READ (1<<0)
+--- a/drivers/gpu/drm/i915/intel_i2c.c
++++ b/drivers/gpu/drm/i915/intel_i2c.c
+@@ -276,18 +276,17 @@ gmbus_wait_idle(struct drm_i915_private
+ }
+
+ static int
+-gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
+- u32 gmbus1_index)
++gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv,
++ unsigned short addr, u8 *buf, unsigned int len,
++ u32 gmbus1_index)
+ {
+ int reg_offset = dev_priv->gpio_mmio_base;
+- u16 len = msg->len;
+- u8 *buf = msg->buf;
+
+ I915_WRITE(GMBUS1 + reg_offset,
+ gmbus1_index |
+ GMBUS_CYCLE_WAIT |
+ (len << GMBUS_BYTE_COUNT_SHIFT) |
+- (msg->addr << GMBUS_SLAVE_ADDR_SHIFT) |
++ (addr << GMBUS_SLAVE_ADDR_SHIFT) |
+ GMBUS_SLAVE_READ | GMBUS_SW_RDY);
+ while (len) {
+ int ret;
+@@ -309,11 +308,35 @@ gmbus_xfer_read(struct drm_i915_private
+ }
+
+ static int
+-gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg)
++gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
++ u32 gmbus1_index)
+ {
+- int reg_offset = dev_priv->gpio_mmio_base;
+- u16 len = msg->len;
+ u8 *buf = msg->buf;
++ unsigned int rx_size = msg->len;
++ unsigned int len;
++ int ret;
++
++ do {
++ len = min(rx_size, GMBUS_BYTE_COUNT_MAX);
++
++ ret = gmbus_xfer_read_chunk(dev_priv, msg->addr,
++ buf, len, gmbus1_index);
++ if (ret)
++ return ret;
++
++ rx_size -= len;
++ buf += len;
++ } while (rx_size != 0);
++
++ return 0;
++}
++
++static int
++gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv,
++ unsigned short addr, u8 *buf, unsigned int len)
++{
++ int reg_offset = dev_priv->gpio_mmio_base;
++ unsigned int chunk_size = len;
+ u32 val, loop;
+
+ val = loop = 0;
+@@ -325,8 +348,8 @@ gmbus_xfer_write(struct drm_i915_private
+ I915_WRITE(GMBUS3 + reg_offset, val);
+ I915_WRITE(GMBUS1 + reg_offset,
+ GMBUS_CYCLE_WAIT |
+- (msg->len << GMBUS_BYTE_COUNT_SHIFT) |
+- (msg->addr << GMBUS_SLAVE_ADDR_SHIFT) |
++ (chunk_size << GMBUS_BYTE_COUNT_SHIFT) |
++ (addr << GMBUS_SLAVE_ADDR_SHIFT) |
+ GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
+ while (len) {
+ int ret;
+@@ -343,6 +366,29 @@ gmbus_xfer_write(struct drm_i915_private
+ if (ret)
+ return ret;
+ }
++
++ return 0;
++}
++
++static int
++gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg)
++{
++ u8 *buf = msg->buf;
++ unsigned int tx_size = msg->len;
++ unsigned int len;
++ int ret;
++
++ do {
++ len = min(tx_size, GMBUS_BYTE_COUNT_MAX);
++
++ ret = gmbus_xfer_write_chunk(dev_priv, msg->addr, buf, len);
++ if (ret)
++ return ret;
++
++ buf += len;
++ tx_size -= len;
++ } while (tx_size != 0);
++
+ return 0;
+ }
+
--- /dev/null
+From fd99a0943ffaa0320ea4f69d09ed188f950c0432 Mon Sep 17 00:00:00 2001
+From: Alex Deucher <alexander.deucher@amd.com>
+Date: Tue, 24 Feb 2015 11:29:21 -0500
+Subject: drm/radeon: fix doublescan modes (v2)
+
+From: Alex Deucher <alexander.deucher@amd.com>
+
+commit fd99a0943ffaa0320ea4f69d09ed188f950c0432 upstream.
+
+Use the correct flags for atom.
+
+v2: handle DRM_MODE_FLAG_DBLCLK
+
+Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/gpu/drm/radeon/atombios_crtc.c | 8 ++++++--
+ 1 file changed, 6 insertions(+), 2 deletions(-)
+
+--- a/drivers/gpu/drm/radeon/atombios_crtc.c
++++ b/drivers/gpu/drm/radeon/atombios_crtc.c
+@@ -312,8 +312,10 @@ atombios_set_crtc_dtd_timing(struct drm_
+ misc |= ATOM_COMPOSITESYNC;
+ if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+ misc |= ATOM_INTERLACE;
+- if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
++ if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+ misc |= ATOM_DOUBLE_CLOCK_MODE;
++ if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
++ misc |= ATOM_H_REPLICATIONBY2 | ATOM_V_REPLICATIONBY2;
+
+ args.susModeMiscInfo.usAccess = cpu_to_le16(misc);
+ args.ucCRTC = radeon_crtc->crtc_id;
+@@ -356,8 +358,10 @@ static void atombios_crtc_set_timing(str
+ misc |= ATOM_COMPOSITESYNC;
+ if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+ misc |= ATOM_INTERLACE;
+- if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
++ if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+ misc |= ATOM_DOUBLE_CLOCK_MODE;
++ if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
++ misc |= ATOM_H_REPLICATIONBY2 | ATOM_V_REPLICATIONBY2;
+
+ args.susModeMiscInfo.usAccess = cpu_to_le16(misc);
+ args.ucCRTC = radeon_crtc->crtc_id;
--- /dev/null
+From 28423ad283d5348793b0c45cc9b1af058e776fd6 Mon Sep 17 00:00:00 2001
+From: Calvin Owens <calvinowens@fb.com>
+Date: Tue, 13 Jan 2015 13:16:18 -0800
+Subject: ksoftirqd: Enable IRQs and call cond_resched() before poking RCU
+
+From: Calvin Owens <calvinowens@fb.com>
+
+commit 28423ad283d5348793b0c45cc9b1af058e776fd6 upstream.
+
+While debugging an issue with excessive softirq usage, I encountered the
+following note in commit 3e339b5dae24a706 ("softirq: Use hotplug thread
+infrastructure"):
+
+ [ paulmck: Call rcu_note_context_switch() with interrupts enabled. ]
+
+...but despite this note, the patch still calls RCU with IRQs disabled.
+
+This seemingly innocuous change caused a significant regression in softirq
+CPU usage on the sending side of a large TCP transfer (~1 GB/s): when
+introducing 0.01% packet loss, the softirq usage would jump to around 25%,
+spiking as high as 50%. Before the change, the usage would never exceed 5%.
+
+Moving the call to rcu_note_context_switch() after the cond_sched() call,
+as it was originally before the hotplug patch, completely eliminated this
+problem.
+
+Signed-off-by: Calvin Owens <calvinowens@fb.com>
+Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
+Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/softirq.c | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+--- a/kernel/softirq.c
++++ b/kernel/softirq.c
+@@ -774,9 +774,13 @@ static void run_ksoftirqd(unsigned int c
+ local_irq_disable();
+ if (local_softirq_pending()) {
+ __do_softirq();
+- rcu_note_context_switch(cpu);
+ local_irq_enable();
+ cond_resched();
++
++ preempt_disable();
++ rcu_note_context_switch(cpu);
++ preempt_enable();
++
+ return;
+ }
+ local_irq_enable();
--- /dev/null
+From 3cab989afd8d8d1bc3d99fef0e7ed87c31e7b647 Mon Sep 17 00:00:00 2001
+From: Al Viro <viro@zeniv.linux.org.uk>
+Date: Fri, 24 Apr 2015 15:47:07 -0400
+Subject: RCU pathwalk breakage when running into a symlink overmounting something
+
+From: Al Viro <viro@zeniv.linux.org.uk>
+
+commit 3cab989afd8d8d1bc3d99fef0e7ed87c31e7b647 upstream.
+
+Calling unlazy_walk() in walk_component() and do_last() when we find
+a symlink that needs to be followed doesn't acquire a reference to vfsmount.
+That's fine when the symlink is on the same vfsmount as the parent directory
+(which is almost always the case), but it's not always true - one _can_
+manage to bind a symlink on top of something. And in such cases we end up
+with excessive mntput().
+
+Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/namei.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+--- a/fs/namei.c
++++ b/fs/namei.c
+@@ -1542,7 +1542,8 @@ static inline int walk_component(struct
+
+ if (should_follow_link(inode, follow)) {
+ if (nd->flags & LOOKUP_RCU) {
+- if (unlikely(unlazy_walk(nd, path->dentry))) {
++ if (unlikely(nd->path.mnt != path->mnt ||
++ unlazy_walk(nd, path->dentry))) {
+ err = -ECHILD;
+ goto out_err;
+ }
+@@ -2824,7 +2825,8 @@ finish_lookup:
+
+ if (should_follow_link(inode, !symlink_ok)) {
+ if (nd->flags & LOOKUP_RCU) {
+- if (unlikely(unlazy_walk(nd, path->dentry))) {
++ if (unlikely(nd->path.mnt != path->mnt ||
++ unlazy_walk(nd, path->dentry))) {
+ error = -ECHILD;
+ goto out;
+ }
ib-mlx4-fix-wqe-lso-segment-calculation.patch
tracing-handle-ftrace_dump-atomic-context-in-graph_trace_open.patch
i2c-core-export-bus-recovery-functions.patch
+drm-radeon-fix-doublescan-modes-v2.patch
+drm-i915-cope-with-large-i2c-transfers.patch
+rcu-pathwalk-breakage-when-running-into-a-symlink-overmounting-something.patch
+ksoftirqd-enable-irqs-and-call-cond_resched-before-poking-rcu.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
