From: Ville Syrjälä Date: Thu, 22 Oct 2020 19:42:56 +0000 (+0300) Subject: drm/modes: Switch to 64bit maths to avoid integer overflow X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5b34ab52401f0f1f191bcb83a182c83b506f4763;p=linux.git drm/modes: Switch to 64bit maths to avoid integer overflow The new >8k CEA modes have dotclocks reaching 5.94 GHz, which means our clock*1000 will now overflow the 32bit unsigned integer. Switch to 64bit maths to avoid it. Cc: stable@vger.kernel.org Reported-by: Randy Dunlap Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20201022194256.30978-1-ville.syrjala@linux.intel.com Tested-by: Randy Dunlap Reviewed-by: Chris Wilson --- diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c index 33fb2f05ce662..1ac67d4505e07 100644 --- a/drivers/gpu/drm/drm_modes.c +++ b/drivers/gpu/drm/drm_modes.c @@ -762,7 +762,7 @@ int drm_mode_vrefresh(const struct drm_display_mode *mode) if (mode->htotal == 0 || mode->vtotal == 0) return 0; - num = mode->clock * 1000; + num = mode->clock; den = mode->htotal * mode->vtotal; if (mode->flags & DRM_MODE_FLAG_INTERLACE) @@ -772,7 +772,7 @@ int drm_mode_vrefresh(const struct drm_display_mode *mode) if (mode->vscan > 1) den *= mode->vscan; - return DIV_ROUND_CLOSEST(num, den); + return DIV_ROUND_CLOSEST_ULL(mul_u32_u32(num, 1000), den); } EXPORT_SYMBOL(drm_mode_vrefresh);