From cbdf98c05644edec4b7a648b3c83d3a1c257ac47 Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Thu, 11 May 2017 13:14:14 -0400 Subject: [PATCH 2/4] drm/radeon/ci: disable mclk switching for high refresh rates (v2) Even if the vblank period would allow it, it still seems to be problematic on some cards. v2: fix logic inversion (Nils) bug: https://bugs.freedesktop.org/show_bug.cgi?id=96868 Signed-off-by: Alex Deucher --- drivers/gpu/drm/radeon/ci_dpm.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/radeon/ci_dpm.c b/drivers/gpu/drm/radeon/ci_dpm.c index 7ba4508..ea36dc4 100644 --- a/drivers/gpu/drm/radeon/ci_dpm.c +++ b/drivers/gpu/drm/radeon/ci_dpm.c @@ -776,6 +776,12 @@ bool ci_dpm_vblank_too_short(struct radeon_device *rdev) u32 vblank_time = r600_dpm_get_vblank_time(rdev); u32 switch_limit = pi->mem_gddr5 ? 450 : 300; + /* disable mclk switching if the refresh is >120Hz, even if the + * blanking period would allow it + */ + if (r600_dpm_get_vrefresh(rdev) > 120) + return true; + if (vblank_time < switch_limit) return true; else -- 2.5.5