Re: [PATCH dev-5.0 2/3] media: platform: aspeed: refine clock control logic

[Eddie James <eajames@linux.ibm.com>]

On 4/9/19 2:20 PM, Jae Hyun Yoo wrote:
> Currently, this driver calls clk_prepare and clk_unprepare from
> interrupt context too but these should be called from sleepable
> context only. To fix this issue, this commit splits out
> clk_enable/disable and clk_prepare/unprepare, and it places
> clk_prepare/unprepare calls into the module probe/remove function.


Reviewed-by: Eddie James <eajames@linux.ibm.com>


>
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> ---
>   drivers/media/platform/aspeed-video.c | 38 ++++++++++++++++++++-------
>   1 file changed, 29 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
> index e70be8fdbde5..75b43488ae8e 100644
> --- a/drivers/media/platform/aspeed-video.c
> +++ b/drivers/media/platform/aspeed-video.c
> @@ -491,8 +491,8 @@ static void aspeed_video_off(struct aspeed_video *video)
>   	aspeed_video_write(video, VE_INTERRUPT_CTRL, 0);
>   
>   	/* Turn off the relevant clocks */
> -	clk_disable_unprepare(video->vclk);
> -	clk_disable_unprepare(video->eclk);
> +	clk_disable(video->vclk);
> +	clk_disable(video->eclk);
>   
>   	clear_bit(VIDEO_CLOCKS_ON, &video->flags);
>   }
> @@ -503,8 +503,8 @@ static void aspeed_video_on(struct aspeed_video *video)
>   		return;
>   
>   	/* Turn on the relevant clocks */
> -	clk_prepare_enable(video->eclk);
> -	clk_prepare_enable(video->vclk);
> +	clk_enable(video->eclk);
> +	clk_enable(video->vclk);
>   
>   	set_bit(VIDEO_CLOCKS_ON, &video->flags);
>   }
> @@ -1628,31 +1628,46 @@ static int aspeed_video_init(struct aspeed_video *video)
>   		return PTR_ERR(video->eclk);
>   	}
>   
> +	rc = clk_prepare(video->eclk);
> +	if (rc)
> +		return rc;
> +
>   	video->vclk = devm_clk_get(dev, "vclk");
>   	if (IS_ERR(video->vclk)) {
>   		dev_err(dev, "Unable to get VCLK\n");
> -		return PTR_ERR(video->vclk);
> +		rc = PTR_ERR(video->vclk);
> +		goto err_unprepare_eclk;
>   	}
>   
> +	rc = clk_prepare(video->vclk);
> +	if (rc)
> +		goto err_unprepare_eclk;
> +
>   	of_reserved_mem_device_init(dev);
>   
>   	rc = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
>   	if (rc) {
>   		dev_err(dev, "Failed to set DMA mask\n");
> -		of_reserved_mem_device_release(dev);
> -		return rc;
> +		goto err_release_reserved_mem;
>   	}
>   
>   	if (!aspeed_video_alloc_buf(video, &video->jpeg,
>   				    VE_JPEG_HEADER_SIZE)) {
>   		dev_err(dev, "Failed to allocate DMA for JPEG header\n");
> -		of_reserved_mem_device_release(dev);
> -		return rc;
> +		goto err_release_reserved_mem;
>   	}
>   
>   	aspeed_video_init_jpeg_table(video->jpeg.virt, video->yuv420);
>   
>   	return 0;
> +
> +err_release_reserved_mem:
> +	of_reserved_mem_device_release(dev);
> +	clk_unprepare(video->vclk);
> +err_unprepare_eclk:
> +	clk_unprepare(video->eclk);
> +
> +	return rc;
>   }
>   
>   static int aspeed_video_probe(struct platform_device *pdev)
> @@ -1696,6 +1711,11 @@ static int aspeed_video_remove(struct platform_device *pdev)
>   	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
>   	struct aspeed_video *video = to_aspeed_video(v4l2_dev);
>   
> +	aspeed_video_off(video);
> +
> +	clk_unprepare(video->vclk);
> +	clk_unprepare(video->eclk);
> +
>   	video_unregister_device(&video->vdev);
>   
>   	vb2_queue_release(&video->queue);