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authorMario Kleiner <mario.kleiner.de@gmail.com>2017-06-13 07:17:11 +0200
committerAlex Deucher <alexander.deucher@amd.com>2017-06-14 15:25:58 +0200
commit55f61a040e1b1ea0ba962e53ae341b4c51915bd1 (patch)
tree16528c7a73bc73fc1fc4aec5046d3c21adec60da /drivers/gpu/drm/radeon/evergreen.c
parentdrm/amdgpu: Fix overflow of watermark calcs at > 4k resolutions. (diff)
downloadlinux-55f61a040e1b1ea0ba962e53ae341b4c51915bd1.tar.xz
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drm/radeon: Fix overflow of watermark calcs at > 4k resolutions.
Commit e6b9a6c84b93 ("drm/radeon: Make display watermark calculations more accurate") made watermark calculations more accurate, but not for > 4k resolutions on 32-Bit architectures, as it introduced an integer overflow for those setups and resolutions. Fix this by proper u64 casting and division. Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com> Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Fixes: e6b9a6c84b93 ("drm/radeon: Make display watermark calculations more accurate") Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/radeon/evergreen.c')
-rw-r--r--drivers/gpu/drm/radeon/evergreen.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 0bf103536404..534637203e70 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -2266,8 +2266,11 @@ static void evergreen_program_watermarks(struct radeon_device *rdev,
fixed20_12 a, b, c;
if (radeon_crtc->base.enabled && num_heads && mode) {
- active_time = 1000000UL * (u32)mode->crtc_hdisplay / (u32)mode->clock;
- line_time = min((u32) (1000000UL * (u32)mode->crtc_htotal / (u32)mode->clock), (u32)65535);
+ active_time = (u32) div_u64((u64)mode->crtc_hdisplay * 1000000,
+ (u32)mode->clock);
+ line_time = (u32) div_u64((u64)mode->crtc_htotal * 1000000,
+ (u32)mode->clock);
+ line_time = min(line_time, (u32)65535);
priority_a_cnt = 0;
priority_b_cnt = 0;
dram_channels = evergreen_get_number_of_dram_channels(rdev);