Re: [PATCH v3 2/3] [media] coda: Check the return value from clk_prepare_enable()

[Philipp Zabel <p.zabel@pengutronix.de>]

Hi Fabio,

Am Montag, den 22.07.2013, 22:38 -0300 schrieb Fabio Estevam:
> From: Fabio Estevam <fabio.estevam@freescale.com>
> 
> clk_prepare_enable() may fail, so let's check its return value and propagate it
> in the case of error.
> 
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> ---
> - Changes since v2:
> - Release the previously acquired resources
> Changes since v1:
> - Add missing 'if'
> 
>  drivers/media/platform/coda.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/coda.c b/drivers/media/platform/coda.c
> index ea16c20..5f15aaa 100644
> --- a/drivers/media/platform/coda.c
> +++ b/drivers/media/platform/coda.c
> @@ -1561,14 +1561,27 @@ static int coda_open(struct file *file)
>  	list_add(&ctx->list, &dev->instances);
>  	coda_unlock(ctx);
>  
> -	clk_prepare_enable(dev->clk_per);
> -	clk_prepare_enable(dev->clk_ahb);
> +	ret = clk_prepare_enable(dev->clk_per);
> +	if (ret)
> +		goto err_clk_per;
> +
> +	ret = clk_prepare_enable(dev->clk_ahb);
> +	if (ret)
> +		goto err_clk_ahb;
>  
>  	v4l2_dbg(1, coda_debug, &dev->v4l2_dev, "Created instance %d (%p)\n",
>  		 ctx->idx, ctx);
>  
>  	return 0;
>  
> +err_clk_ahb:
> +	clk_disable_unprepare(dev->clk_per);
> +err_clk_per:
> +	coda_lock(ctx);
> +	list_del(&ctx->list);
> +	coda_unlock(ctx);
> +	dma_free_coherent(&dev->plat_dev->dev, CODA_PARA_BUF_SIZE,
> +			  ctx->parabuf.vaddr, ctx->parabuf.paddr);
>  err_dma_alloc:
>  	v4l2_ctrl_handler_free(&ctx->ctrls);
>  err_ctrls_setup:

I still think the list_add() should be moved after the last possible
error case and the lock/list_del/unlock should be removed from the error
path.

regards
Philipp