linux/drivers/usb/core
Dan Williams 3cd12f9151 usb: force warm reset to break link re-connect livelock
Resuming a powered down port sometimes results in the port state being
stuck in the training sequence.

 hub 3-0:1.0: debounce: port 1: total 2000ms stable 0ms status 0x2e0
 port1: can't get reconnection after setting port  power on, status -110
 hub 3-0:1.0: port 1 status 0000.02e0 after resume, -19
 usb 3-1: can't resume, status -19
 hub 3-0:1.0: logical disconnect on port 1

In the case above we wait for the port re-connect timeout of 2 seconds
and observe that the port status is USB_SS_PORT_LS_POLLING (although it
is likely toggling between this state and USB_SS_PORT_LS_RX_DETECT).
This is indicative of a case where the device is failing to progress the
link training state machine.

It is resolved by issuing a warm reset to get the hub and device link
state machines back in sync.

 hub 3-0:1.0: debounce: port 1: total 2000ms stable 0ms status 0x2e0
 usb usb3: port1 usb_port_runtime_resume requires warm reset
 hub 3-0:1.0: port 1 not warm reset yet, waiting 50ms
 usb 3-1: reset SuperSpeed USB device number 2 using xhci_hcd

After a reconnect timeout when we expect the device to be present, force
a warm reset of the device.  Note that we can not simply look at the
link status to determine if a warm reset is required as any of the
training states USB_SS_PORT_LS_POLLING, USB_SS_PORT_LS_RX_DETECT, or
USB_SS_PORT_LS_COMP_MOD are valid states that do not indicate the need
for warm reset by themselves.

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Vincent Palatin <vpalatin@chromium.org>
Cc: Lan Tianyu <tianyu.lan@intel.com>
Cc: Ksenia Ragiadakou <burzalodowa@gmail.com>
Cc: Vivek Gautam <gautam.vivek@samsung.com>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Sunil Joshi <joshi@samsung.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Acked-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09 15:43:12 -07:00
..
buffer.c USB: core: correct spelling mistakes in comments and warning 2014-01-07 16:17:40 -08:00
config.c Merge 3.14-rc6 into usb-next 2014-03-12 11:40:15 -07:00
devices.c
devio.c USB patches for 3.15-rc1 2014-04-01 17:06:09 -07:00
driver.c USB: Avoid runtime suspend loops for HCDs that can't handle suspend/resume 2014-05-24 04:06:00 +09:00
endpoint.c
file.c
generic.c staging: usbip: convert usbip-host driver to usb_device_driver 2014-02-07 10:54:30 -08:00
hcd-pci.c usb: remove redundant D0 power state set 2014-05-27 15:18:48 -07:00
hcd.c usb: introduce port status lock 2014-05-27 16:51:50 -07:00
hub.c usb: force warm reset to break link re-connect livelock 2014-07-09 15:43:12 -07:00
hub.h usb: force warm reset to break link re-connect livelock 2014-07-09 15:43:12 -07:00
Kconfig usb: common: rename phy-fsm-usb.c to usb-otg-fsm.c 2014-05-27 15:29:44 -07:00
Makefile USB: core: remove CONFIG_USB_DEBUG usage 2013-12-21 16:01:00 -08:00
message.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2014-04-02 16:23:38 -07:00
notify.c
otg_whitelist.h
port.c usb: force warm reset to break link re-connect livelock 2014-07-09 15:43:12 -07:00
quirks.c usb: Add device quirk for Logitech HD Pro Webcams C920 and C930e 2014-03-07 11:46:51 -08:00
sysfs.c USB: core: correct spelling mistakes in comments and warning 2014-01-07 16:17:40 -08:00
urb.c Merge branch 'master' into for-next 2014-02-20 14:54:28 +01:00
usb-acpi.c usb: find internal hub tier mismatch via acpi 2014-05-27 16:38:52 -07:00
usb.c
usb.h usb: hub_handle_remote_wakeup() depends on CONFIG_PM_RUNTIME=y 2014-05-27 16:51:51 -07:00