lkml.org 
[lkml]   [2013]   [Mar]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[ 38/40] USB: Prepare for refactoring by adding extra udev checks.
Date
3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sarah Sharp <sarah.a.sharp@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.sharp@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@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);



\
 
 \ /
  Last update: 2013-03-13 00:41    [W:0.288 / U:0.264 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site