AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-11-26 07:30:52 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

usb: core: don't try to reset_device() a port that got just disconnected

Browse Source 
The USB hub driver's event handler contains a check to catch SuperSpeed
devices that transitioned into the SS.Inactive state and tries to fix
them with a reset. It decides whether to do a plain hub port reset or
call the usb_reset_device() function based on whether there was a device
attached to the port.

However, there are device/hub combinations (found with a JetFlash
Transcend mass storage stick (8564:1000) on the root hub of an Intel
LynxPoint PCH) which can transition to the SS.Inactive state on
disconnect (and stay there long enough for the host to notice). In this
case, above-mentioned reset check will call usb_reset_device() on the
stale device data structure. The kernel will send pointless LPM control
messages to the no longer connected device address and can even cause
several 5 second khubd stalls on some (buggy?) host controllers, before
finally accepting the device's fate amongst a flurry of error messages.

This patch makes the choice of reset dependent on the port status that
has just been read from the hub in addition to the existence of an
in-kernel data structure for the device, and only proceeds with the more
extensive reset if both are valid.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
This commit is contained in:
Julius Werner 2013-07-30 19:51:20 -07:00 committed by Sarah Sharp
parent fed1f1ed90
commit 481f2d4f89
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/usb/core/hub.c
View File

@ -4798,7 +4798,8 @@ static void hub_events(void)
hub->ports[i - 1]->child;
dev_dbg(hub_dev, "warm reset port %d\n", i);
if (!udev) {
if (!udev || !(portstatus &
USB_PORT_STAT_CONNECTION)) {
status = hub_port_reset(hub, i,
NULL, HUB_BH_RESET_TIME,
true);
@ -4808,8 +4809,8 @@ static void hub_events(void)
usb_lock_device(udev);
status = usb_reset_device(udev);
usb_unlock_device(udev);
connect_change = 0;
}
connect_change = 0;
}
if (connect_change)