diff mbox series

usb: dwc3: Properly handle processing of pending events

Message ID 20230801192658.19275-1-quic_eserrao@quicinc.com (mailing list archive)
State Accepted
Commit 3ddaa6a274578e23745b7466346fc2650df8f959
Headers show
Series usb: dwc3: Properly handle processing of pending events | expand

Commit Message

Elson Roy Serrao Aug. 1, 2023, 7:26 p.m. UTC
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(-)

Comments

Thinh Nguyen Aug. 2, 2023, 12:11 a.m. UTC | #1
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!YtZ93ALEpDNTCEhf0WEyB5S090pPlKIKVtjqTOAEJdxdWbl8QG6eiRmlvfivUtD5qjKWWLX2C4fb4W8VAg5w9qasLuKB$ 
> 
>  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
Roger Quadros Aug. 2, 2023, 2:34 p.m. UTC | #2
On 01/08/2023 22:26, 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>

Reviewed-by: Roger Quadros <rogerq@kernel.org>
diff mbox series

Patch

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);
 	}