[PATCH] media: cedrus: Fix clock/reset sequence

Paul Kocialkowski paul.kocialkowski at bootlin.com
Fri Sep 15 03:03:28 PDT 2023


Hi Jernej,

On Mon 11 Sep 23, 20:46, Jernej Skrabec wrote:
> According to H6 user manual, resets should always be de-asserted before
> clocks are enabled. This is also consistent with vendor driver.

You're right, thanks for the patch!

Acked-by: Paul Kocialkowski <paul.kocialkowski at bootlin.com>

Cheers,

Paul

> Fixes: d5aecd289bab ("media: cedrus: Implement runtime PM")
> Signed-off-by: Jernej Skrabec <jernej.skrabec at gmail.com>
> ---
>  .../staging/media/sunxi/cedrus/cedrus_hw.c    | 24 +++++++++----------
>  1 file changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> index b696bf884cbd..32af0e96e762 100644
> --- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> +++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> @@ -172,12 +172,12 @@ int cedrus_hw_suspend(struct device *device)
>  {
>  	struct cedrus_dev *dev = dev_get_drvdata(device);
>  
> -	reset_control_assert(dev->rstc);
> -
>  	clk_disable_unprepare(dev->ram_clk);
>  	clk_disable_unprepare(dev->mod_clk);
>  	clk_disable_unprepare(dev->ahb_clk);
>  
> +	reset_control_assert(dev->rstc);
> +
>  	return 0;
>  }
>  
> @@ -186,11 +186,18 @@ int cedrus_hw_resume(struct device *device)
>  	struct cedrus_dev *dev = dev_get_drvdata(device);
>  	int ret;
>  
> +	ret = reset_control_reset(dev->rstc);
> +	if (ret) {
> +		dev_err(dev->dev, "Failed to apply reset\n");
> +
> +		return ret;
> +	}
> +
>  	ret = clk_prepare_enable(dev->ahb_clk);
>  	if (ret) {
>  		dev_err(dev->dev, "Failed to enable AHB clock\n");
>  
> -		return ret;
> +		goto err_rst;
>  	}
>  
>  	ret = clk_prepare_enable(dev->mod_clk);
> @@ -207,21 +214,14 @@ int cedrus_hw_resume(struct device *device)
>  		goto err_mod_clk;
>  	}
>  
> -	ret = reset_control_reset(dev->rstc);
> -	if (ret) {
> -		dev_err(dev->dev, "Failed to apply reset\n");
> -
> -		goto err_ram_clk;
> -	}
> -
>  	return 0;
>  
> -err_ram_clk:
> -	clk_disable_unprepare(dev->ram_clk);
>  err_mod_clk:
>  	clk_disable_unprepare(dev->mod_clk);
>  err_ahb_clk:
>  	clk_disable_unprepare(dev->ahb_clk);
> +err_rst:
> +	reset_control_assert(dev->rstc);
>  
>  	return ret;
>  }
> -- 
> 2.42.0
> 

-- 
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com
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