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@xxxxxxxxxxxxxxx
> Fixes: fc8bb91bc83e ("usb: dwc3: implement runtime PM")
> Signed-off-by: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
> ---
> 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@xxxxxxxxxxx/__;!!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@xxxxxxxxxxxx>
Thanks,
Thinh
