Re: drivers/media/test-drivers/vimc/vimc-sensor.c:107:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead.

[Geert Uytterhoeven]

On Mon, 20 Apr 2026 at 19:29, kernel test robot <lkp@xxxxxxxxx> wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   faeab166167f5787719eb8683661fd41a3bb1514
> commit: ec1e620b245495121535bf5c046c6885c7e409cb media: vimc: sensor: Add pixel_rate,vblank and hblank configuration
> date:   5 weeks ago
> config: sparc64-randconfig-r064-20260419
> compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 5bac06718f502014fade905512f1d26d578a18f3)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Fixes: ec1e620b2454 ("media: vimc: sensor: Add pixel_rate,vblank and hblank configuration")
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202604191731.10nxGZ92-lkp@xxxxxxxxx/
>
> cocci warnings: (new ones prefixed by >>)
> >> drivers/media/test-drivers/vimc/vimc-sensor.c:107:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead.
>
> vim +107 drivers/media/test-drivers/vimc/vimc-sensor.c
>
>     94
>     95  static int vimc_sensor_update_frame_timing(struct v4l2_subdev *sd,
>     96                                             u32 width, u32 height)
>     97  {
>     98          struct vimc_sensor_device *vsensor =
>     99                  container_of(sd, struct vimc_sensor_device, sd);
>    100          u64 pixel_rate = vsensor->pixel_rate->val;

v4l2_ctrl.val is s32, not u64.

>    101          u32 hts = width + vsensor->hblank->val;
>    102          u32 vts = height + vsensor->vblank->val;
>    103          u64 total_pixels = (u64)hts * vts;

mul_u32_u32()

>    104          u64 frame_interval_ns;
>    105
>    106          frame_interval_ns = total_pixels * NSEC_PER_SEC;
>  > 107          do_div(frame_interval_ns, pixel_rate);
>    108          vsensor->hw.fps_jiffies = nsecs_to_jiffies(frame_interval_ns);
>    109          if (vsensor->hw.fps_jiffies == 0)
>    110                  vsensor->hw.fps_jiffies = 1;
>    111
>    112          return 0;
>    113  }
>    114

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds