Messages in this thread | ![/](/images/icornerl.gif) | | From | Dmitry Baryshkov <> | Date | Tue, 2 Jan 2024 13:19:42 +0200 | Subject | Re: [PATCH] media: venus: use div64_u64() instead of do_div() |
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On Fri, 29 Dec 2023 at 14:16, Himanshu Bhavani <himanshu.bhavani@siliconsignals.io> wrote: > > do_div() does a 64-by-32 division. > When the divisor is u64, do_div() truncates it to 32 bits, this means it > can test non-zero and be truncated to zero for division. > > fix do_div.cocci warning: > do_div() does a 64-by-32 division, please consider using div64_u64 instead. > > Signed-off-by: Himanshu Bhavani <himanshu.bhavani@siliconsignals.io> > > diff --git a/drivers/media/platform/qcom/venus/venc.c b/drivers/media/platform/qcom/venus/venc.c > index 44b13696cf82..81853eb2993a 100644 > --- a/drivers/media/platform/qcom/venus/venc.c > +++ b/drivers/media/platform/qcom/venus/venc.c > @@ -409,13 +409,13 @@ static int venc_s_parm(struct file *file, void *fh, struct v4l2_streamparm *a) > out->capability = V4L2_CAP_TIMEPERFRAME; > > us_per_frame = timeperframe->numerator * (u64)USEC_PER_SEC; > - do_div(us_per_frame, timeperframe->denominator); > + div64_u64(us_per_frame, timeperframe->denominator);
NAK! This is completely incorrect. do_div() is a macro and it changes the first argument. div64_u64 is a function, which returns the result instead of changing the first argument.
Please consider checking the code before sending a patch.
> > if (!us_per_frame) > return -EINVAL; > > fps = (u64)USEC_PER_SEC; > - do_div(fps, us_per_frame); > + div64_u64(fps, us_per_frame); > > inst->timeperframe = *timeperframe; > inst->fps = fps; > -- > 2.25.1 > >
-- With best wishes Dmitry
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