kernel_optimize_test/drivers/usb/core
Julius Werner 481f2d4f89 usb: core: don't try to reset_device() a port that got just disconnected
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>
2013-07-31 09:51:45 -07:00
..
buffer.c
config.c usb: Fail a get config when the port is powered off. 2012-09-10 13:04:01 -07:00
devices.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
devio.c Merge 3.10-rc5 into usb-next 2013-06-08 21:27:51 -07:00
driver.c PM / Runtime: Rework the "runtime idle" helper routine 2013-06-03 21:49:52 +02:00
endpoint.c usb/endpoint: Set release callback in the struct device_type instead of in the device itself directly 2012-08-20 14:38:08 -07:00
file.c USB: fix PTR_ERR translation in init_usb_class() 2013-06-06 12:14:38 -07:00
generic.c USB: avoid error messages when a device is disconnected 2013-03-28 11:05:52 -07:00
hcd-pci.c USB: improve port transitions when EHCI starts up 2013-03-28 14:45:57 -07:00
hcd.c Allow the USB HCD to create Wireless USB root hubs 2013-06-03 10:52:40 -07:00
hub.c usb: core: don't try to reset_device() a port that got just disconnected 2013-07-31 09:51:45 -07:00
hub.h USB: global suspend and remote wakeup don't mix 2013-07-16 15:33:02 -07:00
Kconfig USB: remove remaining instances of USB_SUSPEND 2013-05-15 13:44:44 -04:00
Makefile usb: Add driver/usb/core/(port.c,hub.h) files 2013-01-18 15:49:00 -08:00
message.c usb: message: Fixed parenthesis error in sizeof function. 2013-05-17 10:09:26 -07:00
notify.c
otg_whitelist.h
port.c Power management and ACPI updates for 3.11-rc1 2013-07-03 14:35:40 -07:00
quirks.c USB: reset resume quirk needed by a hub 2013-05-16 17:28:28 -07:00
sysfs.c usb: add usb2 Link PM variables to sysfs and usb_device 2013-06-05 16:48:40 -07:00
urb.c USB: fix urb-poison imbalance 2013-03-25 13:48:27 -07:00
usb-acpi.c usb/acpi: binding xhci root hub usb port with ACPI 2013-03-25 10:39:17 -07:00
usb.c usb: ehci: Only sleep for post-resume handover if devices use persist 2013-05-20 11:28:55 -07:00
usb.h USB: remove CONFIG_USB_SUSPEND option 2013-03-28 11:10:22 -07:00