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

From: Doug Anderson
Date: Thu Oct 29 2015 - 12:44:01 EST


On Thu, Oct 22, 2015 at 1:05 PM, Douglas Anderson <dianders@xxxxxxxxxxxx> 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@xxxxxxxxxxxx>
> ---
> 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.


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