USB: add flag for HCDs that can't receive wakeup requests (isp1760-hcd)

commit 074f9dd55f9cab1b82690ed7e44bcf38b9616ce0 upstream.

Currently the USB stack assumes that all host controller drivers are
capable of receiving wakeup requests from downstream devices.
However, this isn't true for the isp1760-hcd driver, which means that
it isn't safe to do a runtime suspend of any device attached to a
root-hub port if the device requires wakeup.

This patch adds a "cant_recv_wakeups" flag to the usb_hcd structure
and sets the flag in isp1760-hcd.  The core is modified to prevent a
direct child of the root hub from being put into runtime suspend with
wakeup enabled if the flag is set.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 4aeb10034de7c0db94333d66c4e98bf4df9052f5..37c7ce9af22089eed3bae2ce1d61d350ea3e765b 100644 (file)
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1800,6 +1800,18 @@ static int autosuspend_check(struct usb_device *udev)
                dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
                return -EOPNOTSUPP;
        }
+
+       /*
+        * If the device is a direct child of the root hub and the HCD
+        * doesn't handle wakeup requests, don't allow autosuspend when
+        * wakeup is needed.
+        */
+       if (w && udev->parent == udev->bus->root_hub &&
+                       bus_to_hcd(udev->bus)->cant_recv_wakeups) {
+               dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n");
+               return -EOPNOTSUPP;
+       }
+
        udev->do_remote_wakeup = w;
        return 0;
 }

diff --git a/drivers/usb/host/isp1760-hcd.c b/drivers/usb/host/isp1760-hcd.c
index 51a0ae9cdd1d27ead9bac1146c257996e697dd3f..5ea7c6bdfd28bb2fb333b9391ed6fa1d912d72c0 100644 (file)
--- a/drivers/usb/host/isp1760-hcd.c
+++ b/drivers/usb/host/isp1760-hcd.c
@@ -2247,6 +2247,9 @@ struct usb_hcd *isp1760_register(phys_addr_t res_start, resource_size_t res_len,
        hcd->rsrc_start = res_start;
        hcd->rsrc_len = res_len;
 
+       /* This driver doesn't support wakeup requests */
+       hcd->cant_recv_wakeups = 1;
+
        ret = usb_add_hcd(hcd, irq, irqflags);
        if (ret)
                goto err_unmap;

diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 52598bdce2babbb62417335ff78dbc05dfbdb6e4..6e98f62ea70d619b648b0d41ec62380549402cfc 100644 (file)
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -144,6 +144,8 @@ struct usb_hcd {
        unsigned                has_tt:1;       /* Integrated TT in root hub */
        unsigned                amd_resume_bug:1; /* AMD remote wakeup quirk */
        unsigned                can_do_streams:1; /* HC supports streams */
+       unsigned                cant_recv_wakeups:1;
+                       /* wakeup requests from downstream aren't received */
 
        unsigned int            irq;            /* irq allocated */
        void __iomem            *regs;          /* device memory/io */