drm/radeon: Fix overflow of watermark calcs at > 4k resolutions.

Commit e6b9a6c84b
("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: e6b9a6c84b ("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>
This commit is contained in:
Mario Kleiner 2017-06-13 07:17:11 +02:00 committed by Alex Deucher
parent bea1041393
commit 55f61a040e
3 changed files with 15 additions and 6 deletions

View file

@ -9267,8 +9267,11 @@ static void dce8_program_watermarks(struct radeon_device *rdev,
u32 tmp, wm_mask;
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);
/* watermark for high clocks */
if ((rdev->pm.pm_method == PM_METHOD_DPM) &&

View file

@ -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);

View file

@ -2284,8 +2284,11 @@ static void dce6_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;