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authorJulius Werner <jwerner@chromium.org>2013-07-30 19:51:20 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-14 22:59:10 -0700
commit6b9cb24deb2e856b111f77415e9a7da9b09020f6 (patch)
tree3f5189651c06d64f3e2d078c6ee0b60147382303
parent94bcc7deb8fed472360ad72ef3717c5409057fca (diff)
downloadvexpress-lsk-6b9cb24deb2e856b111f77415e9a7da9b09020f6.tar.gz
usb: core: don't try to reset_device() a port that got just disconnected
commit 481f2d4f89f87a0baa26147f323380e31cfa7c44 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/core/hub.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b93fc88c482..da2905a1a18 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4796,7 +4796,8 @@ 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);
@@ -4806,8 +4807,8 @@ 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)