[PATCH v2] drm/pl111: Use 64-bit arithmetic instead of 32-bit

From: Gustavo A. R. Silva
Date: Wed Jul 04 2018 - 10:23:40 EST


Add suffix ULL to constant 1000 in order to give the compiler complete
information about the proper arithmetic to use.

Notice that such constant is used in a context that expects an
expression of type u64 (64 bits, unsigned) and the following
expression is currently being evaluated using 32-bit arithmetic:

mode->clock * 1000

Addresses-Coverity-ID: 1466139 ("Unintentional integer overflow")
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
Changes in v2:
- Use suffix ULL instead of UL.

drivers/gpu/drm/pl111/pl111_display.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/pl111/pl111_display.c b/drivers/gpu/drm/pl111/pl111_display.c
index a432eb7..754f6b2 100644
--- a/drivers/gpu/drm/pl111/pl111_display.c
+++ b/drivers/gpu/drm/pl111/pl111_display.c
@@ -63,7 +63,7 @@ pl111_mode_valid(struct drm_crtc *crtc,
* We use the pixelclock to also account for interlaced modes, the
* resulting bandwidth is in bytes per second.
*/
- bw = mode->clock * 1000; /* In Hz */
+ bw = mode->clock * 1000ULL; /* In Hz */
bw = bw * mode->hdisplay * mode->vdisplay * cpp;
bw = div_u64(bw, mode->htotal * mode->vtotal);

--
2.7.4