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| author | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2013-03-07 16:24:22 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-14 11:29:51 -0700 |
| commit | e850004e595d6322c6b7ccbfe21a4582051ad56b (patch) | |
| tree | 250637573ab5224f068a63723d461ac6d7a7c2ba /drivers | |
| parent | ac79dc9b4a929bd8c0d9e4a2fccd3b7215cbaee4 (diff) | |
| download | lwn-e850004e595d6322c6b7ccbfe21a4582051ad56b.tar.gz lwn-e850004e595d6322c6b7ccbfe21a4582051ad56b.zip | |
USB: Prepare for refactoring by adding extra udev checks.
[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.sharp@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/core/hub.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 6aceaec90530..2e1ec69c07d3 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2253,6 +2253,9 @@ static int hub_port_wait_reset(struct usb_hub *hub, int port1, 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 usb_hub *hub, int port1, 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 usb_hub *hub, int port1, 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); |