From: Dave Stevenson <dave.stevenson@raspberrypi.org>
To: natechancellor@gmail.com
Cc: Eric Anholt <eric@anholt.net>,
Stefan Wahren <stefan.wahren@i2se.com>,
Greg KH <gregkh@linuxfoundation.org>,
devel@driverdev.osuosl.org, ndesaulniers@google.com,
linux-kernel@vger.kernel.org,
"moderated list:BROADCOM BCM2835 ARM ARCHITECTURE"
<linux-rpi-kernel@lists.infradead.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] staging: bcm2835-camera: Avoid unneeded internal declaration warning
Date: Fri, 28 Sep 2018 10:04:29 +0100 [thread overview]
Message-ID: <CAAoAYcMMiiDXCcnZ=DP9Y9Xs+xdq-jasj8G_W0jrnQV9so79=A@mail.gmail.com> (raw)
In-Reply-To: <20180928005038.1697-1-natechancellor@gmail.com>
Hi Nate
Thanks for the patch.
On Fri, 28 Sep 2018 at 01:53, Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> Clang warns:
>
> drivers/staging/vc04_services/bcm2835-camera/controls.c:59:18: warning:
> variable 'mains_freq_qmenu' is not needed and will not be emitted
> [-Wunneeded-internal-declaration]
> static const s64 mains_freq_qmenu[] = {
> ^
> 1 warning generated.
>
> This is because mains_freq_qmenu is currently only used in an ARRAY_SIZE
> macro, which is a compile time evaluation in this case. Avoid this by
> adding mains_freq_qmenu as the imenu member of this structure, which
> matches all other controls that uses the ARRAY_SIZE macro in v4l2_ctrls.
> This turns out to be a no-op because V4L2_CID_MPEG_VIDEO_BITRATE_MODE is
> defined as a MMAL_CONTROL_TYPE_STD_MENU, which does not pass the imenu
> definition along to v4l2_ctrl_new in bm2835_mmal_init_controls.
There's a slight confusion betwen V4L2_CID_MPEG_VIDEO_BITRATE_MODE and
V4L2_CID_POWER_LINE_FREQUENCY in your description.
However you're right that MMAL_CONTROL_TYPE_STD_MENU calls
v4l2_ctrl_new_std_menu which doesn't need a menu array (it's
v4l2_ctrl_new_int_menu that does). That means the correct fix is to
define the max value using the relevant enum (in this case
V4L2_CID_POWER_LINE_FREQUENCY_AUTO) and remove the array.
The same is true for V4L2_CID_MPEG_VIDEO_BITRATE_MODE - max should be
V4L2_MPEG_VIDEO_BITRATE_MODE_CBR, and remove the bitrate_mode_qmenu
array.
Thanks,
Dave
> Link: https://github.com/ClangBuiltLinux/linux/issues/122
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> drivers/staging/vc04_services/bcm2835-camera/controls.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/vc04_services/bcm2835-camera/controls.c b/drivers/staging/vc04_services/bcm2835-camera/controls.c
> index cff7b1e07153..a2c55cb2192a 100644
> --- a/drivers/staging/vc04_services/bcm2835-camera/controls.c
> +++ b/drivers/staging/vc04_services/bcm2835-camera/controls.c
> @@ -1106,7 +1106,7 @@ static const struct bm2835_mmal_v4l2_ctrl v4l2_ctrls[V4L2_CTRL_COUNT] = {
> {
> V4L2_CID_POWER_LINE_FREQUENCY, MMAL_CONTROL_TYPE_STD_MENU,
> 0, ARRAY_SIZE(mains_freq_qmenu) - 1,
> - 1, 1, NULL,
> + 1, 1, mains_freq_qmenu,
> MMAL_PARAMETER_FLICKER_AVOID,
> &ctrl_set_flicker_avoidance,
> false
> --
> 2.19.0
>
>
> _______________________________________________
> linux-rpi-kernel mailing list
> linux-rpi-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rpi-kernel
next prev parent reply other threads:[~2018-09-28 9:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-28 0:50 [PATCH] staging: bcm2835-camera: Avoid unneeded internal declaration warning Nathan Chancellor
2018-09-28 9:04 ` Dave Stevenson [this message]
2018-09-28 14:48 ` Nathan Chancellor
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