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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index cc13abf..c105ba3 100644 (file)
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1664,6 +1664,18 @@ static int autosuspend_check(struct usb_device *udev)
                dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n");
                return -EOPNOTSUPP;
        }
                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;
 }
        udev->do_remote_wakeup = w;
        return 0;
 }

diff --git a/drivers/usb/host/isp1760-hcd.c b/drivers/usb/host/isp1760-hcd.c
index 27dfab8..a4c2369 100644 (file)
--- a/drivers/usb/host/isp1760-hcd.c
+++ b/drivers/usb/host/isp1760-hcd.c
@@ -2254,6 +2254,9 @@ 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;
 
        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;
        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 112bc91..4fc3e5d 100644 (file)
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -128,6 +128,8 @@ struct usb_hcd {
        unsigned                wireless:1;     /* Wireless USB HCD */
        unsigned                authorized_default:1;
        unsigned                has_tt:1;       /* Integrated TT in root hub */
        unsigned                wireless:1;     /* Wireless USB HCD */
        unsigned                authorized_default:1;
        unsigned                has_tt:1;       /* Integrated TT in root hub */

+       unsigned                cant_recv_wakeups:1;
+                       /* wakeup requests from downstream aren't received */

 
        int                     irq;            /* irq allocated */
        void __iomem            *regs;          /* device memory/io */
 
        int                     irq;            /* irq allocated */
        void __iomem            *regs;          /* device memory/io */