Re: [PATCH] drm/modes: Prevent division by zero htotal

Daniel Vetter
2019-01-23T10:56:23Z

On Wed, Jan 23, 2019 at 03:28:59PM +0800, Tina Zhang wrote:
> This patch prevents division by zero htotal.

How did you manage to get here with htotal == 0? This needs backtraces
(or if this is just about static checkers, a mention of that).
-Daniel

>
> Signed-off-by: Tina Zhang <tina.zhang@intel.com>
> Cc: Adam Jackson <ajax@redhat.com>
> Cc: Dave Airlie <airlied@redhat.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> ---
> drivers/gpu/drm/drm_modes.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
> index adce9a2..59b92b1 100644
> --- a/drivers/gpu/drm/drm_modes.c
> +++ b/drivers/gpu/drm/drm_modes.c
> @@ -751,7 +751,7 @@ int drm_mode_hsync(const struct drm_display_mode *mode)
> if (mode->hsync)
> return mode->hsync;
>
> - if (mode->htotal < 0)
> + if (mode->htotal <= 0)
> return 0;
>
> calc_val = (mode->clock * 1000) / mode->htotal; /* hsync in Hz */
> --
> 2.7.4
>

--
Daniel Vetter
Software Engineer, Intel Corporation