3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sarah Sharp <sarah.a.sh...@linux.intel.com>
[This is upstream commit 2d4fa940f99663c82ba55b2244638833b388e4e2.
It needs to be backported to kernels as old as 3.2, because it fixes the
buggy commit 9dbcaec830cd97f44a0b91b315844e0d7144746b "USB: Handle warm
reset failure on empty port."]
The next patch will refactor the hub port code to rip out the recursive
call to hub_port_reset on a failed hot reset. In preparation for that,
make sure all code paths can deal with being called with a NULL udev.
The usb_device will not be valid if warm reset was issued because a port
transitioned to the Inactive or Compliance Mode on a device connect.
This patch should have no effect on current behavior.
Signed-off-by: Sarah Sharp <sarah.a.sh...@linux.intel.com>
Acked-by: Alan Stern <st...@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/usb/core/hub.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2253,6 +2253,9 @@ static int hub_port_wait_reset(struct us
return -ENOTCONN;
if ((portstatus & USB_PORT_STAT_ENABLE)) {
+ if (!udev)
+ return 0;
+
if (hub_is_wusb(hub))
udev->speed = USB_SPEED_WIRELESS;
else if (hub_is_superspeed(hub->hdev))
@@ -2296,13 +2299,15 @@ static void hub_port_finish_reset(struct
struct usb_hcd *hcd;
/* TRSTRCY = 10 ms; plus some extra */
msleep(10 + 40);
- update_devnum(udev, 0);
- hcd = bus_to_hcd(udev->bus);
- /* The xHC may think the device is already reset,
- * so ignore the status.
- */
- if (hcd->driver->reset_device)
- hcd->driver->reset_device(hcd, udev);
+ if (udev) {
+ update_devnum(udev, 0);
+ hcd = bus_to_hcd(udev->bus);
+ /* The xHC may think the device is already
+ * reset, so ignore the status.
+ */
+ if (hcd->driver->reset_device)
+ hcd->driver->reset_device(hcd, udev);
+ }
}
/* FALL THROUGH */
case -ENOTCONN:
@@ -2316,7 +2321,7 @@ static void hub_port_finish_reset(struct
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_PORT_LINK_STATE);
}
- if (!warm)
+ if (!warm && udev)
usb_set_device_state(udev, *status
? USB_STATE_NOTATTACHED
: USB_STATE_DEFAULT);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
