[PATCH] usb: dwc2: host: Fix remote wakeup when not in DWC2_L2

John Youn John.Youn at synopsys.com
Thu Oct 29 20:21:29 PDT 2015

On 10/29/2015 9:43 AM, Doug Anderson wrote:
> John,
> On Thu, Oct 22, 2015 at 1:05 PM, Douglas Anderson <dianders at chromium.org> wrote:
>> In commit 734643dfbdde ("usb: dwc2: host: add flag to reflect bus
>> state") we changed dwc2_port_suspend() not to set the lx_state
>> anymore (instead it sets the new bus_suspended variable).  This
>> introduced a bug where we would fail to detect device insertions if:
>> 1. Plug empty hub into dwc2
>> 2. Plug USB flash drive into the empty hub.
>> 3. Wait a few seconds
>> 4. Unplug USB flash drive
>> 5. Less than 2 seconds after step 4, plug the USB flash drive in again.
>> The dwc2_hcd_rem_wakeup() function should have been changed to look at
>> the new bus_suspended variable.
>> Let's fix it.  Since commit b46146d59fda ("usb: dwc2: host: resume root
>> hub on remote wakeup") talks about needing the root hub resumed if the
>> bus was suspended, we'll include it in our test.
>> It appears that the "port_l1_change" should only be set to 1 if we were
>> in DWC2_L1 (the driver currently never sets this), so we'll update the
>> former "else" case based on this test.
>> Fixes: 734643dfbdde ("usb: dwc2: host: add flag to reflect bus state")
>> Signed-off-by: Douglas Anderson <dianders at chromium.org>
>> ---
>>  drivers/usb/dwc2/hcd.c | 9 +++++----
>>  1 file changed, 5 insertions(+), 4 deletions(-)
> I know I've sent up a lot of patches recently, but this one in
> particular would be good to get tested, reviewed, and landed sooner
> rather than later.  I believe it fixes a recent regression that is
> probably experienced across all dwc2 users.
> Please let me know if you have any questions.

Acked-by: John Youn <johnyoun at synopsys.com>

Sorry for the delay. I'll get to the others soon.

Yousaf, Gregory,

Care to provide reviewed or tested-bys?


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