[PATCH] media: imx-pxp: Initialize the spinlock prior to using it

[PATCH] media: imx-pxp: Initialize the spinlock prior to using it

[Fabio Estevam]

After devm_request_threaded_irq() is called there is a chance that an
interrupt may occur before the spinlock is initialized, which will trigger
a kernel oops.

To prevent that, move the initialization of the spinlock prior to
requesting the interrupts.

Fixes: 51abcf7fdb70 ("media: imx-pxp: add i.MX Pixel Pipeline driver")
Signed-off-by: Fabio Estevam <festevam@denx.de>
---
 drivers/media/platform/imx-pxp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/imx-pxp.c b/drivers/media/platform/imx-pxp.c
index acfc77f9d58f..7d1768ec7fcd 100644
--- a/drivers/media/platform/imx-pxp.c
+++ b/drivers/media/platform/imx-pxp.c
@@ -1693,6 +1693,8 @@ static int pxp_probe(struct platform_device *pdev)
 	if (irq < 0)
 		return irq;
 
+	spin_lock_init(&dev->irqlock);
+
 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, pxp_irq_handler,
 			IRQF_ONESHOT, dev_name(&pdev->dev), dev);
 	if (ret < 0) {
@@ -1710,8 +1712,6 @@ static int pxp_probe(struct platform_device *pdev)
 		goto err_clk;
 	}
 
-	spin_lock_init(&dev->irqlock);
-
 	ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
 	if (ret)
 		goto err_clk;
-- 
2.25.1

Re: [PATCH] media: imx-pxp: Initialize the spinlock prior to using it

[Philipp Zabel]

Hi Fabio,

On Thu, 2021-10-07 at 10:56 -0300, Fabio Estevam wrote:
> After devm_request_threaded_irq() is called there is a chance that an
> interrupt may occur before the spinlock is initialized, which will trigger
> a kernel oops.
>
> To prevent that, move the initialization of the spinlock prior to
> requesting the interrupts.
> 
> Fixes: 51abcf7fdb70 ("media: imx-pxp: add i.MX Pixel Pipeline driver")
> Signed-off-by: Fabio Estevam <festevam@denx.de>
> ---
>  drivers/media/platform/imx-pxp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/imx-pxp.c b/drivers/media/platform/imx-pxp.c
> index acfc77f9d58f..7d1768ec7fcd 100644
> --- a/drivers/media/platform/imx-pxp.c
> +++ b/drivers/media/platform/imx-pxp.c
> @@ -1693,6 +1693,8 @@ static int pxp_probe(struct platform_device *pdev)
>  	if (irq < 0)
>  		return irq;
>  
> +	spin_lock_init(&dev->irqlock);
> +
>  	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, pxp_irq_handler,
>  			IRQF_ONESHOT, dev_name(&pdev->dev), dev);
>  	if (ret < 0) {
> @@ -1710,8 +1712,6 @@ static int pxp_probe(struct platform_device *pdev)
>  		goto err_clk;
>  	}
>  
> -	spin_lock_init(&dev->irqlock);
> -
>  	ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
>  	if (ret)
>  		goto err_clk;

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp