[PATCH 4/5] drm/amdgpu/cgs: add refresh rate checking to non-DC display code

[Alex Deucher]

Clamp the vblank period to 0 if the refresh rate is larger than
120 hz for non-DC.  This allows us to remove the refresh rate
checks from powerplay for mclk switching.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c
index 71b4aec7f650..dc3360b16bda 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c
@@ -953,6 +953,11 @@ static int amdgpu_cgs_get_active_displays_info(struct cgs_device *cgs_device,
 								(amdgpu_crtc->v_border * 2);
 					mode_info->vblank_time_us = vblank_lines * line_time_us;
 					mode_info->refresh_rate = drm_mode_vrefresh(&amdgpu_crtc->hw_mode);
+					/* we have issues with mclk switching with refresh rates
+					 * over 120 hz on the non-DC code.
+					 */
+					if (mode_info->refresh_rate > 120)
+						mode_info->vblank_time_us = 0;
 					mode_info = NULL;
 				}
 			}
-- 
2.13.6