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

From: Gustavo A. R. Silva
Date: Sun Aug 11 2019 - 20:12:26 EST


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@xxxxxxxxxxxxxx>
---
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