From: Alex Deucher Date: Wed, 12 Oct 2016 19:28:55 +0000 (-0400) Subject: drm/radeon: change vblank_time's calculation method to reduce computational error. X-Git-Tag: v5.15~12629^2~1^2~11 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=02cfb5fccb0f9f968f0e208d89d9769aa16267bc;p=platform%2Fkernel%2Flinux-starfive.git drm/radeon: change vblank_time's calculation method to reduce computational error. Ported from Rex's amdgpu change. Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org --- diff --git a/drivers/gpu/drm/radeon/r600_dpm.c b/drivers/gpu/drm/radeon/r600_dpm.c index 6a4b020..5a26eb4 100644 --- a/drivers/gpu/drm/radeon/r600_dpm.c +++ b/drivers/gpu/drm/radeon/r600_dpm.c @@ -156,19 +156,20 @@ u32 r600_dpm_get_vblank_time(struct radeon_device *rdev) struct drm_device *dev = rdev->ddev; struct drm_crtc *crtc; struct radeon_crtc *radeon_crtc; - u32 line_time_us, vblank_lines; + u32 vblank_in_pixels; u32 vblank_time_us = 0xffffffff; /* if the displays are off, vblank time is max */ if (rdev->num_crtc && rdev->mode_info.mode_config_initialized) { list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) { radeon_crtc = to_radeon_crtc(crtc); if (crtc->enabled && radeon_crtc->enabled && radeon_crtc->hw_mode.clock) { - line_time_us = (radeon_crtc->hw_mode.crtc_htotal * 1000) / - radeon_crtc->hw_mode.clock; - vblank_lines = radeon_crtc->hw_mode.crtc_vblank_end - - radeon_crtc->hw_mode.crtc_vdisplay + - (radeon_crtc->v_border * 2); - vblank_time_us = vblank_lines * line_time_us; + vblank_in_pixels = + radeon_crtc->hw_mode.crtc_htotal * + (radeon_crtc->hw_mode.crtc_vblank_end - + radeon_crtc->hw_mode.crtc_vdisplay + + (radeon_crtc->v_border * 2)); + + vblank_time_us = vblank_in_pixels * 1000 / radeon_crtc->hw_mode.clock; break; } }