Re: [PATCH] can: flexcan: Fix an uninitialized variable issue

From: Marc Kleine-Budde
Date: Thu Jul 29 2021 - 07:31:16 EST


On 29.07.2021 13:27:42, Christophe JAILLET wrote:
> If both 'clk_ipg' and 'clk_per' are NULL, we return an un-init value.
> So set 'err' to 0, to return success in such a case.

Thanks for the patch, a similar one has been posted before:
https://lore.kernel.org/linux-can/20210728075428.1493568-1-mkl@xxxxxxxxxxxxxx/

> Fixes: d9cead75b1c6 ("can: flexcan: add mcf5441x support")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> Another way to fix it is to remove the NULL checks for 'clk_ipg' and
> 'clk_per' that been added in commit d9cead75b1c6.
>
> They look useless to me because 'clk_prepare_enable()' returns 0 if it is
> passed a NULL pointer.

ACK, while the common clock framework's clk_prepare_enable() can handle
NULL pointers, the clock framework used on the mcf5441x doesn't.

> Having these explicit tests is maybe informational (i.e. these pointers
> can really be NULL) or have been added to silent a compiler or a static
> checker.
>
> So, in case, I've left the tests and just fixed the un-init 'err' variable
> issue.

regards,
Marc

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