Re: [PATCH v2 23/26] media: venus: vdec: Make explicit the range of us_per_frame

From: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
To: Ricardo Ribalda <ribalda@chromium.org>,
	Martin Tuma <martin.tuma@digiteqautomotive.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Hugues Fruchet <hugues.fruchet@foss.st.com>,
	Alain Volmat <alain.volmat@foss.st.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Paul Kocialkowski <paul.kocialkowski@bootlin.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Chen-Yu Tsai <wens@csie.org>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	Samuel Holland <samuel@sholland.org>,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Sowjanya Komatineni <skomatineni@nvidia.com>,
	Luca Ceresoli <luca.ceresoli@bootlin.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno
	<angelogioacchino.delregno@collabora.com>,
	Hans Verkuil <hverkuil@xs4all.nl>, Sergey Kozlov <serjk@netup.ru>,
	Abylay Ospan <aospan@netup.ru>,
	Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>,
	Dmitry Osipenko <digetx@gmail.com>,
	Benjamin Mugnier <benjamin.mugnier@foss.st.com>,
	Sylvain Petinot <sylvain.petinot@foss.st.com>,
	Stanimir Varbanov <stanimir.k.varbanov@gmail.com>,
	Vikash Garodia <quic_vgarodia@quicinc.com>,
	Bjorn Andersson <andersson@kernel.org>,
	Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org,
	linux-staging@lists.linux.dev, linux-sunxi@lists.linux.dev,
	linux-tegra@vger.kernel.org, linux-mediatek@lists.infradead.org,
	linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH v2 23/26] media: venus: vdec: Make explicit the range of us_per_frame
Date: Sat, 20 Apr 2024 23:47:01 +0100	[thread overview]
Message-ID: <0b5c6091-e47c-4d24-a13a-2b5ad1b9cfb8@linaro.org> (raw)
In-Reply-To: <20240419-fix-cocci-v2-23-2119e692309c@chromium.org>

On 19/04/2024 10:48, Ricardo Ribalda wrote:
> Unless the fps is smaller than 0.000232829 fps, this fits in a 32 bit
> number. Make that explicit.
> 
> Found by cocci:
> drivers/media/platform/qcom/venus/vdec.c:488:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead.
> 
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>   drivers/media/platform/qcom/venus/vdec.c | 7 ++-----
>   1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/venus/vdec.c b/drivers/media/platform/qcom/venus/vdec.c
> index 29130a9441e7..2b2874aedb2d 100644
> --- a/drivers/media/platform/qcom/venus/vdec.c
> +++ b/drivers/media/platform/qcom/venus/vdec.c
> @@ -464,7 +464,7 @@ static int vdec_s_parm(struct file *file, void *fh, struct v4l2_streamparm *a)
>   	struct venus_inst *inst = to_inst(file);
>   	struct v4l2_captureparm *cap = &a->parm.capture;
>   	struct v4l2_fract *timeperframe = &cap->timeperframe;
> -	u64 us_per_frame, fps;
> +	u64 us_per_frame;
>   
>   	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE &&
>   	    a->type != V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
> @@ -484,10 +484,7 @@ static int vdec_s_parm(struct file *file, void *fh, struct v4l2_streamparm *a)
>   	if (!us_per_frame)
>   		return -EINVAL;
>   
> -	fps = (u64)USEC_PER_SEC;
> -	do_div(fps, us_per_frame);
> -
> -	inst->fps = fps;
> +	inst->fps = USEC_PER_SEC / (u32)us_per_frame;
>   	inst->timeperframe = *timeperframe;
>   
>   	return 0;
> 

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>