linux-kernel - Re: [PATCH] media: s5p-mfc: Handle error for clk

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Message-ID: <56c49d7f-33be-3d99-af65-edbf19a960c9@intel.com>
Date:   Tue, 8 Mar 2022 11:50:21 +0100
From:   Andrzej Hajda <andrzej.hajda@...el.com>
To:     Jiasheng Jiang <jiasheng@...as.ac.cn>, <m.szyprowski@...sung.com>,
        <mchehab@...nel.org>
CC:     <linux-arm-kernel@...ts.infradead.org>,
        <linux-media@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] media: s5p-mfc: Handle error for clk_enable

Hi,

On 08.03.2022 08:55, Jiasheng Jiang wrote:
> As the potential failure of the clk_enable(),
> it should be better to check it and return error
> if fails.

It does not seem to be real issue. More below.


>
> Fixes: 1bce6fb3edf1 ("[media] s5p-mfc: Rework clock handling")
> Signed-off-by: Jiasheng Jiang <jiasheng@...as.ac.cn>
> ---
>   drivers/media/platform/s5p-mfc/s5p_mfc_pm.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c b/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c
> index 88b7d33c9197..392e6fab0a75 100644
> --- a/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c
> +++ b/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c
> @@ -106,10 +106,12 @@ int s5p_mfc_power_on(void)
>   
>   int s5p_mfc_power_off(void)
>   {
> -	int i;
> +	int i, ret;
>   
>   	/* finish software clock gating */
> -	clk_enable(pm->clock_gate);
> +	ret = clk_enable(pm->clock_gate);
> +	if (ret)
> +		return ret;

Here clk_enable is just for balance enable counter for pm->clocks[0]. It 
does not matter if it succeeds, as it will be disabled in next lines.
For sure failure here should not stop power off sequence.

Regards
Andrzej

>   
>   	for (i = 0; i < pm->num_clocks; i++)
>   		clk_disable_unprepare(pm->clocks[i]);