Re: [PATCH v2] media: cx18: Don't check for address of video_dev

From: Nick Desaulniers
Date: Mon Oct 01 2018 - 19:06:42 EST


On Mon, Oct 1, 2018 at 8:22 AM Nathan Chancellor
<natechancellor@xxxxxxxxx> wrote:
>
> Clang warns that the address of a pointer will always evaluated as true
> in a boolean context.
>
> drivers/media/pci/cx18/cx18-driver.c:1255:23: warning: address of
> 'cx->streams[i].video_dev' will always evaluate to 'true'
> [-Wpointer-bool-conversion]
> if (&cx->streams[i].video_dev)
> ~~ ~~~~~~~~~~~~~~~^~~~~~~~~
> 1 warning generated.
>
> Check whether v4l2_dev is null, not the address, so that the statement
> doesn't fire all the time. This check has been present since 2009,
> introduced by commit 21a278b85d3c ("V4L/DVB (11619): cx18: Simplify the
> work handler for outgoing mailbox commands")
>
> Reported-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> ---
>
> v1 -> v2:
>
> * Fix build error and logic per review from Hans
>
> drivers/media/pci/cx18/cx18-driver.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/pci/cx18/cx18-driver.c b/drivers/media/pci/cx18/cx18-driver.c
> index 56763c4ea1a7..a6ba4ca5aa91 100644
> --- a/drivers/media/pci/cx18/cx18-driver.c
> +++ b/drivers/media/pci/cx18/cx18-driver.c
> @@ -1252,7 +1252,7 @@ static void cx18_cancel_out_work_orders(struct cx18 *cx)
> {
> int i;
> for (i = 0; i < CX18_MAX_STREAMS; i++)
> - if (&cx->streams[i].video_dev)
> + if (cx->streams[i].video_dev.v4l2_dev)

There we go, that looks better! Thanks for respinning this patch. I
would've given Hans credit in a Suggested-by tag, but there's not
necessarily strict rules on that (and doesn't necessitate a v3).
Maybe the maintainer could apply that to the commit message when
applying? Either way:

Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

> cancel_work_sync(&cx->streams[i].out_work_order);
> }
>
> --
> 2.19.0
>


--
Thanks,
~Nick Desaulniers