This is a note to let you know that I've just added the patch titled USB: Prepare for refactoring by adding extra udev checks. to the 3.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-prepare-for-refactoring-by-adding-extra-udev-checks.patch and it can be found in the queue-3.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From sarah.a.sharp@xxxxxxxxxxxxxxx Tue Mar 12 14:58:36 2013 From: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> Date: Thu, 7 Mar 2013 16:23:34 -0800 Subject: USB: Prepare for refactoring by adding extra udev checks. To: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Message-ID: <20130308002334.GA13297@xanatos> From: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> [This is upstream commit 2d4fa940f99663c82ba55b2244638833b388e4e2. It needs to be backported to kernels as old as 3.2, because it fixes the buggy commit 65bdac5effd15d6af619b3b7218627ef4d84ed6a "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.sharp@xxxxxxxxxxxxxxx> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -2584,6 +2584,9 @@ 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)) @@ -2627,13 +2630,15 @@ 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: @@ -2647,7 +2652,7 @@ 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); Patches currently in stable-queue which might be from sarah.a.sharp@xxxxxxxxxxxxxxx are queue-3.8/usb-don-t-use-ehci-port-sempahore-for-usb-3.0-hubs.patch queue-3.8/usb-rip-out-recursive-call-on-warm-port-reset.patch queue-3.8/usb-prepare-for-refactoring-by-adding-extra-udev-checks.patch queue-3.8/usb-fix-connected-device-switch-to-inactive-state.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html