diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2014-05-29 12:58:46 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-09 15:43:12 -0700 |
| commit | 3cd12f91514da6893954de479dc60b16d3b381f4 (patch) | |
| tree | 3209b05551050ac2e1da7f79ca96bc49298f9ac9 /drivers/usb/core/hub.h | |
| parent | 51df62ff74b371866c1006dee887a8e42838c1f2 (diff) | |
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>
Diffstat (limited to 'drivers/usb/core/hub.h')
| -rw-r--r-- | drivers/usb/core/hub.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h index 326308e53961..c77d8778af4b 100644 --- a/drivers/usb/core/hub.h +++ b/drivers/usb/core/hub.h @@ -52,6 +52,8 @@ struct usb_hub { unsigned long power_bits[1]; /* ports that are powered */ unsigned long child_usage_bits[1]; /* ports powered on for children */ + unsigned long warm_reset_bits[1]; /* ports requesting warm + reset recovery */ #if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */ #error event_bits[] is too short! #endif |