Re: [PATCH] usb: dwc3: omap: remove IRQ_NOAUTOEN used with shared irq

[Grygorii Strashko]

On 07/07/2017 01:22 AM, Vignesh R wrote:
> IRQ_NOAUTOEN cannot be used with shared IRQs, since commit 04c848d39879
> ("genirq: Warn when IRQ_NOAUTOEN is used with shared interrupts") and
> kernel now throws a warn dump. But OMAP DWC3 driver uses this flag. As
> per commit 12a7f17fac5b ("usb: dwc3: omap: fix race of pm runtime with
> irq handler in probe") that introduced this flag, PM runtime can race
> with IRQ handler when deferred probing happens due to extcon,
> therefore IRQ_NOAUTOEN needs to be set so that irq is not enabled until
> extcon is registered.
>
> Remove setting of IRQ_NOAUTOEN and move the registration of
> shared irq to a point after dwc3_omap_extcon_register() and
> of_platform_populate(). This avoids possibility of probe deferring and
> above said race condition.
>
> Signed-off-by: Vignesh R <vigneshr@xxxxxx>


Reviewed-by: Grygorii Strashko <grygorii.strashko@xxxxxx>

> ---
>   drivers/usb/dwc3/dwc3-omap.c | 18 ++++++++----------
>   1 file changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c
> index 98926504b55b..f5aaa0cf3873 100644
> --- a/drivers/usb/dwc3/dwc3-omap.c
> +++ b/drivers/usb/dwc3/dwc3-omap.c
> @@ -512,15 +512,6 @@ static int dwc3_omap_probe(struct platform_device *pdev)
>   
>   	/* check the DMA Status */
>   	reg = dwc3_omap_readl(omap->base, USBOTGSS_SYSCONFIG);
> -	irq_set_status_flags(omap->irq, IRQ_NOAUTOEN);
> -	ret = devm_request_threaded_irq(dev, omap->irq, dwc3_omap_interrupt,
> -					dwc3_omap_interrupt_thread, IRQF_SHARED,
> -					"dwc3-omap", omap);
> -	if (ret) {
> -		dev_err(dev, "failed to request IRQ #%d --> %d\n",
> -				omap->irq, ret);
> -		goto err1;
> -	}
>   
>   	ret = dwc3_omap_extcon_register(omap);
>   	if (ret < 0)
> @@ -532,8 +523,15 @@ static int dwc3_omap_probe(struct platform_device *pdev)
>   		goto err1;
>   	}
>   
> +	ret = devm_request_threaded_irq(dev, omap->irq, dwc3_omap_interrupt,
> +					dwc3_omap_interrupt_thread, IRQF_SHARED,
> +					"dwc3-omap", omap);
> +	if (ret) {
> +		dev_err(dev, "failed to request IRQ #%d --> %d\n",
> +			omap->irq, ret);
> +		goto err1;
> +	}
>   	dwc3_omap_enable_irqs(omap);
> -	enable_irq(omap->irq);
>   	return 0;
>   
>   err1:

--
regards,
-grygorii