lkml.org 
[lkml]   [2022]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 4/8] usb: dwc3: qcom: fix runtime PM wakeup
On Thu, Aug 04, 2022 at 09:35:16AM +0200, Johan Hovold wrote:
> On Wed, Aug 03, 2022 at 02:58:33PM -0700, Matthias Kaehlcke wrote:
> > On Tue, Aug 02, 2022 at 05:14:00PM +0200, Johan Hovold wrote:
> > > A device must enable wakeups during runtime suspend regardless of
> > > whether it is capable and allowed to wake the system up from system
> > > suspend.
> > >
> > > Fixes: 2664deb09306 ("usb: dwc3: qcom: Honor wakeup enabled/disabled state")
> > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> >
> > Ah, I wasn't aware that the same wakeup mechanism is used in runtime suspend.
> >
> > In how far is runtime PM actually supported/used by this driver? The device is
> > set 'active' in _probe(), and there are no other pm_runtime_* calls, except
> > in dwc3_qcom_remove() and qcom_dwc3_resume_irq(). How does the device get from
> > 'active' into 'suspended'?
>
> It will be runtime suspended when the child (core) device suspends, but
> you need to enable runtime PM through sysfs first.

Thanks for the clarification.

After enabling runtime suspend for the dwc3 core, dwc3 glue and the xHCI
the dwc3-qcom enters autosuspend when the delay expires.

> And the controller is resumed in the wakeup-interrupt handler for the
> runtime PM case.
>
> It seems to work ok, and it looks like the driver has supported this
> since it was first merged.

With and without your patch dwc3-qcom enters autosuspend and stays there.
USB devices like a mouse or a USB to Ethernet adapter keep working while
the glue is suspended.

How is the runtime resume triggered for the dwc3 glue?

Sorry if my questions are very basic, so far I haven't dealt much with
autosuspend and I'm trying to get a better understanding in the context
of the dwc3 and why it is currently broken.

\
 
 \ /
  Last update: 2022-08-04 17:36    [W:0.088 / U:0.404 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site