On 06/01/2025 14:40, Ricardo Ribalda wrote: > Fps bigger than 0.000232829 fps, this fits in a 32 bit us_per_frame. > There is no need to do a 64 bit division here. > Also, the driver only works with whole fps. > > 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. > > Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx> > Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx> > --- > 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 6b8906ced6bc..88f6b5a3a4fe 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) > @@ -486,10 +486,7 @@ static int vdec_s_parm(struct file *file, void *fh, struct v4l2_streamparm *a) > if (!us_per_frame || us_per_frame > USEC_PER_SEC) > 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; This still allows for an fps value of USEC_PER_SEC if us_per_frame is 1. Looking at where inst->fps is used I see: drivers/media/platform/qcom/venus/pm_helpers.c: return mbs * inst->fps; drivers/media/platform/qcom/venus/venc.c: frate.framerate = inst->fps * (1 << 16); (mbs is at most 512x512) So if fps is USEC_PER_SEC those calculations will wrap around. What is the real maximum fps that the HW can handle? Stan? Bryan? It would be nice if there is a proper sanity check here. Regards, Hans > timeperframe->numerator = 1; > timeperframe->denominator = inst->fps; > >
