From bea10413934dcf98cb9b2dfcdc56e1d28f192897 Mon Sep 17 00:00:00 2001 From: Mario Kleiner Date: Tue, 13 Jun 2017 07:17:10 +0200 Subject: drm/amdgpu: Fix overflow of watermark calcs at > 4k resolutions. Commit d63c277dc672e0 ("drm/amdgpu: 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: d63c277dc672 ("drm/amdgpu: 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/amd/amdgpu/dce_v10_0.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/amd/amdgpu/dce_v10_0.c') diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c index 0cdeb6a2e4a0..5dffa27afa45 100644 --- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c +++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c @@ -1207,8 +1207,11 @@ static void dce_v10_0_program_watermarks(struct amdgpu_device *adev, u32 tmp, wm_mask, lb_vblank_lead_lines = 0; if (amdgpu_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 (adev->pm.dpm_enabled) { -- cgit v1.2.3