From: Kai-Heng Feng kai.heng.feng@canonical.com
commit 227545b9a08c68778ddd89428f99c351fc9315ac upstream.
Screen flickers rapidly when two 4K 60Hz monitors are in use. This issue doesn't happen when one monitor is 4K 60Hz (pixelclock 594MHz) and another one is 4K 30Hz (pixelclock 297MHz).
The issue is gone after setting "power_dpm_force_performance_level" to "high". Following the indication, we found that the issue occurs when sclk is too low.
So resolve the issue by disabling sclk switching when there are two monitors requires high pixelclock (> 297MHz).
v2: - Only apply the fix to Oland. Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/radeon/radeon.h | 1 + drivers/gpu/drm/radeon/radeon_pm.c | 8 ++++++++ drivers/gpu/drm/radeon/si_dpm.c | 3 +++ 3 files changed, 12 insertions(+)
--- a/drivers/gpu/drm/radeon/radeon.h +++ b/drivers/gpu/drm/radeon/radeon.h @@ -1562,6 +1562,7 @@ struct radeon_dpm { void *priv; u32 new_active_crtcs; int new_active_crtc_count; + int high_pixelclock_count; u32 current_active_crtcs; int current_active_crtc_count; bool single_display; --- a/drivers/gpu/drm/radeon/radeon_pm.c +++ b/drivers/gpu/drm/radeon/radeon_pm.c @@ -1715,6 +1715,7 @@ static void radeon_pm_compute_clocks_dpm struct drm_device *ddev = rdev->ddev; struct drm_crtc *crtc; struct radeon_crtc *radeon_crtc; + struct radeon_connector *radeon_connector;
if (!rdev->pm.dpm_enabled) return; @@ -1724,6 +1725,7 @@ static void radeon_pm_compute_clocks_dpm /* update active crtc counts */ rdev->pm.dpm.new_active_crtcs = 0; rdev->pm.dpm.new_active_crtc_count = 0; + rdev->pm.dpm.high_pixelclock_count = 0; if (rdev->num_crtc && rdev->mode_info.mode_config_initialized) { list_for_each_entry(crtc, &ddev->mode_config.crtc_list, head) { @@ -1731,6 +1733,12 @@ static void radeon_pm_compute_clocks_dpm if (crtc->enabled) { rdev->pm.dpm.new_active_crtcs |= (1 << radeon_crtc->crtc_id); rdev->pm.dpm.new_active_crtc_count++; + if (!radeon_crtc->connector) + continue; + + radeon_connector = to_radeon_connector(radeon_crtc->connector); + if (radeon_connector->pixelclock_for_modeset > 297000) + rdev->pm.dpm.high_pixelclock_count++; } } } --- a/drivers/gpu/drm/radeon/si_dpm.c +++ b/drivers/gpu/drm/radeon/si_dpm.c @@ -3000,6 +3000,9 @@ static void si_apply_state_adjust_rules( (rdev->pdev->device == 0x6605)) { max_sclk = 75000; } + + if (rdev->pm.dpm.high_pixelclock_count > 1) + disable_sclk_switching = true; }
if (rps->vce_active) {