drm/komeda: Fix potential integer overflow in komeda_crtc_update_clock_ratio

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@embeddedor.com>
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: james qian wang (Arm Technology China) <james.qian.wang@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190812000801.GA29204@embeddedor

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index fa9a459..624d257 100644 (file)
--- 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);