diff options
| author | Colin Ian King <colin.king@canonical.com> | 2020-09-15 17:20:49 +0100 |
|---|---|---|
| committer | Heiko Stuebner <heiko@sntech.de> | 2021-05-28 20:27:44 +0200 |
| commit | ce0cb93a5adb283f577cd4661f511047b5e39028 (patch) | |
| tree | 9c9f907905d7619ce37e2d15a70bf96692561452 /drivers/gpu/drm/rockchip | |
| parent | 3dfa159f6b0c054eb63673fbf643a5f2cc862e63 (diff) | |
drm/rockchip: cdn-dp: fix sign extension on an int multiply for a u64 result
The variable bit_per_pix is a u8 and is promoted in the multiplication
to an int type and then sign extended to a u64. If the result of the
int multiplication is greater than 0x7fffffff then the upper 32 bits will
be set to 1 as a result of the sign extension. Avoid this by casting
tu_size_reg to u64 to avoid sign extension and also a potential overflow.
Fixes: 1a0f7ed3abe2 ("drm/rockchip: cdn-dp: add cdn DP support for rk3399")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200915162049.36434-1-colin.king@canonical.com
Diffstat (limited to 'drivers/gpu/drm/rockchip')
| -rw-r--r-- | drivers/gpu/drm/rockchip/cdn-dp-reg.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.c b/drivers/gpu/drm/rockchip/cdn-dp-reg.c index 9d2163ef4d6e..33fb4d05c506 100644 --- a/drivers/gpu/drm/rockchip/cdn-dp-reg.c +++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.c @@ -658,7 +658,7 @@ int cdn_dp_config_video(struct cdn_dp_device *dp) */ do { tu_size_reg += 2; - symbol = tu_size_reg * mode->clock * bit_per_pix; + symbol = (u64)tu_size_reg * mode->clock * bit_per_pix; do_div(symbol, dp->max_lanes * link_rate * 8); rem = do_div(symbol, 1000); if (tu_size_reg > 64) { |