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[4/5] usb: dwc3: qcom: Clear pending interrupt before enabling wake interrupt

Message ID 20230325165217.31069-5-manivannan.sadhasivam@linaro.org
State New
Headers show
Series usb: dwc3: qcom: Allow runtime PM | expand

Commit Message

Manivannan Sadhasivam March 25, 2023, 4:52 p.m. UTC
It is possible that there may be a pending interrupt logged into the dwc IP
while the interrupts were disabled in the driver. And when the wakeup
interrupt is enabled, the pending interrupt might fire which is not
required to be serviced by the driver.

So always clear the pending interrupt before enabling wake interrupt.

Cc: stable@vger.kernel.org # 5.20
Fixes: 360e8230516d ("usb: dwc3: qcom: Add helper functions to enable,disable wake irqs")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/usb/dwc3/dwc3-qcom.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Johan Hovold March 28, 2023, 9:28 a.m. UTC | #1
On Sat, Mar 25, 2023 at 10:22:16PM +0530, Manivannan Sadhasivam wrote:
> It is possible that there may be a pending interrupt logged into the dwc IP
> while the interrupts were disabled in the driver. And when the wakeup
> interrupt is enabled, the pending interrupt might fire which is not
> required to be serviced by the driver.
> 
> So always clear the pending interrupt before enabling wake interrupt.
> 
> Cc: stable@vger.kernel.org # 5.20
> Fixes: 360e8230516d ("usb: dwc3: qcom: Add helper functions to enable,disable wake irqs")
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index bbf67f705d0d..f1059dfcb0e8 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -346,6 +346,8 @@ static void dwc3_qcom_enable_wakeup_irq(int irq, unsigned int polarity)
>  	if (!irq)
>  		return;
>  
> +	irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, 0);
> +

This looks like a hack (and a layering violation). Note that there are
no other non-irqchip drivers calling this function.

>  	if (polarity)
>  		irq_set_irq_type(irq, polarity);

Johan
Manivannan Sadhasivam March 28, 2023, 9:50 a.m. UTC | #2
On Tue, Mar 28, 2023 at 11:28:32AM +0200, Johan Hovold wrote:
> On Sat, Mar 25, 2023 at 10:22:16PM +0530, Manivannan Sadhasivam wrote:
> > It is possible that there may be a pending interrupt logged into the dwc IP
> > while the interrupts were disabled in the driver. And when the wakeup
> > interrupt is enabled, the pending interrupt might fire which is not
> > required to be serviced by the driver.
> > 
> > So always clear the pending interrupt before enabling wake interrupt.
> > 
> > Cc: stable@vger.kernel.org # 5.20
> > Fixes: 360e8230516d ("usb: dwc3: qcom: Add helper functions to enable,disable wake irqs")
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> >  drivers/usb/dwc3/dwc3-qcom.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > index bbf67f705d0d..f1059dfcb0e8 100644
> > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > @@ -346,6 +346,8 @@ static void dwc3_qcom_enable_wakeup_irq(int irq, unsigned int polarity)
> >  	if (!irq)
> >  		return;
> >  
> > +	irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, 0);
> > +
> 
> This looks like a hack (and a layering violation). Note that there are
> no other non-irqchip drivers calling this function.
> 

I can check if this can be achieved by clearing some dwc specific registers.

- Mani

> >  	if (polarity)
> >  		irq_set_irq_type(irq, polarity);
> 
> Johan
diff mbox series

Patch

diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index bbf67f705d0d..f1059dfcb0e8 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -346,6 +346,8 @@  static void dwc3_qcom_enable_wakeup_irq(int irq, unsigned int polarity)
 	if (!irq)
 		return;
 
+	irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, 0);
+
 	if (polarity)
 		irq_set_irq_type(irq, polarity);