[PATCH] drm/komeda: Fix potential integer overflow in komeda_crtc_update_clock_ratio

Gustavo A. R. Silva gustavo at embeddedor.com
Mon Aug 12 00:08:01 UTC 2019


Add suffix ULL to constant 1000 in order to avoid a potential integer
overflow and give the compiler complete information about the proper
arithmetic to use. Notice that this constant is being used in a context
that expects an expression of type u64, but it's currently evaluated
using 32-bit arithmetic.

Addresses-Coverity-ID: 1485796 ("Unintentional integer overflow")
Fixes: ed22c6d9304d ("drm/komeda: Use drm_display_mode "crtc_" prefixed hardware timings")
Signed-off-by: Gustavo A. R. Silva <gustavo at embeddedor.com>
---
 drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index fa9a4593bb37..624d257da20f 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -27,7 +27,7 @@ static void komeda_crtc_update_clock_ratio(struct komeda_crtc_state *kcrtc_st)
 		return;
 	}
 
-	pxlclk = kcrtc_st->base.adjusted_mode.crtc_clock * 1000;
+	pxlclk = kcrtc_st->base.adjusted_mode.crtc_clock * 1000ULL;
 	aclk = komeda_crtc_get_aclk(kcrtc_st);
 
 	kcrtc_st->clock_ratio = div64_u64(aclk << 32, pxlclk);
-- 
2.22.0



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