From 55f61a040e1b1ea0ba962e53ae341b4c51915bd1 Mon Sep 17 00:00:00 2001 From: Mario Kleiner Date: Tue, 13 Jun 2017 07:17:11 +0200 Subject: 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 Reported-by: Ben Hutchings Fixes: e6b9a6c84b93 ("drm/radeon: Make display watermark calculations more accurate") Cc: Ben Hutchings Cc: Alex Deucher Cc: stable@vger.kernel.org Signed-off-by: Alex Deucher --- drivers/gpu/drm/radeon/cik.c | 7 +++++-- drivers/gpu/drm/radeon/evergreen.c | 7 +++++-- drivers/gpu/drm/radeon/si.c | 7 +++++-- 3 files changed, 15 insertions(+), 6 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c index 008c145b7f29..ca44233ceacc 100644 --- a/drivers/gpu/drm/radeon/cik.c +++ b/drivers/gpu/drm/radeon/cik.c @@ -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) && 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); diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c index 76d1888528e6..5303f25d5280 100644 --- a/drivers/gpu/drm/radeon/si.c +++ b/drivers/gpu/drm/radeon/si.c @@ -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; -- cgit