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* Re: [PATCH] usb: dwc3: Properly handle processing of pending events
@ 2023-08-02  1:39 庞苏荣 (Surong Pang)
  2023-08-02 14:37 ` Roger Quadros
  0 siblings, 1 reply; 5+ messages in thread
From: 庞苏荣 (Surong Pang) @ 2023-08-02  1:39 UTC (permalink / raw)
  To: Thinh Nguyen, Elson Roy Serrao
  Cc: gregkh@linuxfoundation.org, felipe.balbi@linux.intel.com,
	rogerq@kernel.org, linux-kernel@vger.kernel.org,
	linux-usb@vger.kernel.org, quic_wcheng@quicinc.com,
	quic_jackp@quicinc.com, stable@vger.kernel.org,
	庞苏荣 (Surong Pang)

Dears，
If there is/are event(s) in evt->buf,  in dwc3_check_event_buf,  dwc3_thread_interrupt will be woke up.

> > @@ -4718,6 +4723,8 @@ void dwc3_gadget_process_pending_events(struct
> > dwc3 *dwc)  {
> >       if (dwc->pending_events) {
> >               dwc3_interrupt(dwc->irq_gadget, dwc->ev_buf);
> > +             dwc3_thread_interrupt(dwc->irq_gadget, dwc->ev_buf);
> > +             pm_runtime_put(dwc->dev);
> >               dwc->pending_events = false;
> >               enable_irq(dwc->irq_gadget);
> >       }

I just want to know dwc3_thread_interrupt here is necessary or not?


> On Tue, Aug 02, 2023 8:12 Thinh Nguyen wrote:
>> On Tue, Aug 01, 2023, Elson Roy Serrao wrote:
> > If dwc3 is runtime suspended we defer processing the event buffer
> > until resume, by setting the pending_events flag. Set this flag before
> > triggering resume to avoid race with the runtime resume callback.
> >
> > While handling the pending events, in addition to checking the event
> > buffer we also need to process it. Handle this by explicitly calling
> > dwc3_thread_interrupt(). Also balance the runtime pm get() operation
> > that triggered this processing.
> >
> > Cc: stable@vger.kernel.org
> > Fixes: fc8bb91bc83e ("usb: dwc3: implement runtime PM")
> > Signed-off-by: Elson Roy Serrao <quic_eserrao@quicinc.com>
> > ---
> > Change separated from below series as an independent fix based on the
> > earlier discussion
> > https://urldefense.com/v3/__https://lore.kernel.org/all/be57511d-2005-
> > a1f5-d5a5-809e71029aec@quicinc.com/__;!!A4F2R9G_pg!YtZ93ALEpDNTCEhf0WE
> > yB5S090pPlKIKVtjqTOAEJdxdWbl8QG6eiRmlvfivUtD5qjKWWLX2C4fb4W8VAg5w9qasL
> > uKB$
> >
> >  drivers/usb/dwc3/gadget.c | 9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> > index 5fd067151fbf..858fe4c299b7 100644
> > --- a/drivers/usb/dwc3/gadget.c
> > +++ b/drivers/usb/dwc3/gadget.c
> > @@ -4455,9 +4455,14 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt)
> >       u32 count;
> >
> >       if (pm_runtime_suspended(dwc->dev)) {
> > +             dwc->pending_events = true;
> > +             /*
> > +              * Trigger runtime resume. The get() function will be balanced
> > +              * after processing the pending events in dwc3_process_pending
> > +              * events().
> > +              */
> >               pm_runtime_get(dwc->dev);
> >               disable_irq_nosync(dwc->irq_gadget);
> > -             dwc->pending_events = true;
> >               return IRQ_HANDLED;
> >       }
> >
> > @@ -4718,6 +4723,8 @@ void dwc3_gadget_process_pending_events(struct
> > dwc3 *dwc)  {
> >       if (dwc->pending_events) {
> >               dwc3_interrupt(dwc->irq_gadget, dwc->ev_buf);
> > +             dwc3_thread_interrupt(dwc->irq_gadget, dwc->ev_buf);
> > +             pm_runtime_put(dwc->dev);
> >               dwc->pending_events = false;
> >               enable_irq(dwc->irq_gadget);
> >       }
> > --
> > 2.17.1
> >
> 
> This fix is more complete.
> 
> Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> 
> Thanks,
> Thinh

^ permalink raw reply	[flat|nested] 5+ messages in thread
* [PATCH] usb: dwc3: Properly handle processing of pending events
@ 2023-08-01 19:26 Elson Roy Serrao
  2023-08-02  0:11 ` Thinh Nguyen
  2023-08-02 14:34 ` Roger Quadros
  0 siblings, 2 replies; 5+ messages in thread
From: Elson Roy Serrao @ 2023-08-01 19:26 UTC (permalink / raw)
  To: Thinh.Nguyen, gregkh, felipe.balbi, rogerq, surong.pang
  Cc: linux-kernel, linux-usb, quic_wcheng, quic_jackp,
	Elson Roy Serrao, stable

If dwc3 is runtime suspended we defer processing the event buffer
until resume, by setting the pending_events flag. Set this flag before
triggering resume to avoid race with the runtime resume callback.

While handling the pending events, in addition to checking the event
buffer we also need to process it. Handle this by explicitly calling
dwc3_thread_interrupt(). Also balance the runtime pm get() operation
that triggered this processing.

Cc: stable@vger.kernel.org
Fixes: fc8bb91bc83e ("usb: dwc3: implement runtime PM")
Signed-off-by: Elson Roy Serrao <quic_eserrao@quicinc.com>
---
Change separated from below series as an independent fix based on the
earlier discussion
https://lore.kernel.org/all/be57511d-2005-a1f5-d5a5-809e71029aec@quicinc.com/

 drivers/usb/dwc3/gadget.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 5fd067151fbf..858fe4c299b7 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -4455,9 +4455,14 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt)
 	u32 count;
 
 	if (pm_runtime_suspended(dwc->dev)) {
+		dwc->pending_events = true;
+		/*
+		 * Trigger runtime resume. The get() function will be balanced
+		 * after processing the pending events in dwc3_process_pending
+		 * events().
+		 */
 		pm_runtime_get(dwc->dev);
 		disable_irq_nosync(dwc->irq_gadget);
-		dwc->pending_events = true;
 		return IRQ_HANDLED;
 	}
 
@@ -4718,6 +4723,8 @@ void dwc3_gadget_process_pending_events(struct dwc3 *dwc)
 {
 	if (dwc->pending_events) {
 		dwc3_interrupt(dwc->irq_gadget, dwc->ev_buf);
+		dwc3_thread_interrupt(dwc->irq_gadget, dwc->ev_buf);
+		pm_runtime_put(dwc->dev);
 		dwc->pending_events = false;
 		enable_irq(dwc->irq_gadget);
 	}
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-08-02 14:37 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2023-08-02  1:39 [PATCH] usb: dwc3: Properly handle processing of pending events 庞苏荣 (Surong Pang)
2023-08-02 14:37 ` Roger Quadros
  -- strict thread matches above, loose matches on Subject: below --
2023-08-01 19:26 Elson Roy Serrao
2023-08-02  0:11 ` Thinh Nguyen
2023-08-02 14:34 ` Roger Quadros

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