On 2023/7/18 13:39, Dan Carpenter wrote:
On Mon, Jul 17, 2023 at 04:52:51PM +0200, Andrzej Hajda wrote:
On 17.07.2023 08:22, Su Hui wrote:
Clang warning: drivers/gpu/drm/i915/display/intel_tv.c:
line 991, column 22 Division by zero.
Assuming tv_mode->oversample=1 and (!tv_mode->progressive)=1,
then division by zero will happen.
Fixes: 1bba5543e4fe ("drm/i915: Fix TV encoder clock computation")
Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_tv.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/display/intel_tv.c b/drivers/gpu/drm/i915/display/intel_tv.c
index 36b479b46b60..82b54af51f23 100644
--- a/drivers/gpu/drm/i915/display/intel_tv.c
+++ b/drivers/gpu/drm/i915/display/intel_tv.c
@@ -988,7 +988,8 @@ intel_tv_mode_to_mode(struct drm_display_mode *mode,
const struct tv_mode *tv_mode,
int clock)
{
- mode->clock = clock / (tv_mode->oversample >> !tv_mode->progressive);
+ mode->clock = clock / (tv_mode->oversample != 1 ?
+ tv_mode->oversample >> !tv_mode->progressive : 1);
Seems too smart to me, why not just:
mode->clock = clock / tv_mode->oversample;
if (!tv_mode->progressive)
mode->clock <<= 1;
This is nice.
mode->clock = clock / tv_mode->oversample << !tv_mode->progressive;
But I think this one is much better, it has less code and run faster.
Should I resend v3 to add some explanation or follow Dan's advice?
Su Hui
regards,
dan carpenter
