Re: [PATCH v2 5/9] media: qcom: camss: Fix VFE-480 vfe_disable_output()

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Bryan,

Thank you for the patch.

On Tue, Aug 22, 2023 at 09:06:22PM +0100, Bryan O'Donoghue wrote:
> vfe-480 is copied from vfe-17x and has the same racy idle timeout bug as in
> 17x.
> 
> Fix the vfe_disable_output() logic to no longer be racy and to conform
> to the 17x way of quiescing and then resetting the VFE.

How about dropping the duplicate function and share a single
implementation for the two files ?

> Fixes: 4edc8eae715c ("media: camss: Add initial support for VFE hardware version Titan 480")
> Cc: stable@vger.kernel.org
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> ---
>  .../media/platform/qcom/camss/camss-vfe-480.c | 19 +++----------------
>  1 file changed, 3 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/camss/camss-vfe-480.c b/drivers/media/platform/qcom/camss/camss-vfe-480.c
> index f70aad2e8c237..a64d660abc538 100644
> --- a/drivers/media/platform/qcom/camss/camss-vfe-480.c
> +++ b/drivers/media/platform/qcom/camss/camss-vfe-480.c
> @@ -334,28 +334,15 @@ static int vfe_disable_output(struct vfe_line *line)
>  	struct vfe_output *output = &line->output;
>  	unsigned long flags;
>  	unsigned int i;
> -	bool done;
> -	int timeout = 0;
> -
> -	do {
> -		spin_lock_irqsave(&vfe->output_lock, flags);
> -		done = !output->gen2.active_num;
> -		spin_unlock_irqrestore(&vfe->output_lock, flags);
> -		usleep_range(10000, 20000);
> -
> -		if (timeout++ == 100) {
> -			dev_err(vfe->camss->dev, "VFE idle timeout - resetting\n");
> -			vfe_reset(vfe);
> -			output->gen2.active_num = 0;
> -			return 0;
> -		}
> -	} while (!done);
>  
>  	spin_lock_irqsave(&vfe->output_lock, flags);
>  	for (i = 0; i < output->wm_num; i++)
>  		vfe_wm_stop(vfe, output->wm_idx[i]);
> +	output->gen2.active_num = 0;
>  	spin_unlock_irqrestore(&vfe->output_lock, flags);
>  
> +	vfe_reset(vfe);
> +
>  	return 0;
>  }
>  

-- 
Regards,

Laurent Pinchart