Re: [PATCH] media: mtk-jpeg: Set platform driver data earlier

[AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>]

Il 10/07/23 08:51, Chen-Yu Tsai ha scritto:
> In the multi-core JPEG encoder/decoder setup, the driver for the
> individual cores references the parent device's platform driver data.
> However, in the parent driver, this is only set at the end of the probe
> function, way later than devm_of_platform_populate(), which triggers
> the probe of the cores. This causes a kernel splat in the sub-device
> probe function.
> 
> Move platform_set_drvdata() to before devm_of_platform_populate() to
> fix this.
> 
> Fixes: 934e8bccac95 ("mtk-jpegenc: support jpegenc multi-hardware")
> Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

> ---
> Not sure what caused this to surface just now, given that the driver
> changes were merged in v6.2-rc1, and the corresponding dts entries
> in v6.3-rc1.
> 
> This fixes boot failures on MT8195. Please apply and send to Linus ASAP.
> 
>   drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> index 4768156181c9..6a8eea9dde67 100644
> --- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> +++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
> @@ -1312,6 +1312,8 @@ static int mtk_jpeg_probe(struct platform_device *pdev)
>   	jpeg->dev = &pdev->dev;
>   	jpeg->variant = of_device_get_match_data(jpeg->dev);
>   
> +	platform_set_drvdata(pdev, jpeg);
> +
>   	ret = devm_of_platform_populate(&pdev->dev);
>   	if (ret) {
>   		v4l2_err(&jpeg->v4l2_dev, "Master of platform populate failed.");
> @@ -1383,8 +1385,6 @@ static int mtk_jpeg_probe(struct platform_device *pdev)
>   		  jpeg->variant->dev_name, jpeg->vdev->num,
>   		  VIDEO_MAJOR, jpeg->vdev->minor);
>   
> -	platform_set_drvdata(pdev, jpeg);
> -
>   	pm_runtime_enable(&pdev->dev);
>   
>   	return 0;