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

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

[Vignesh R]

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-l0cyMroinI0@public.gmane.org>
---
 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:
-- 
2.13.0

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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@ti.com>


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

> ---
>   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