drm/radeon/dpm: Disable sclk switching on Oland when two 4K 60Hz monitors are connected

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>

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index aa3b589f30a18a57bffa3fd04ffb39b75bdc22f8..1d6130563fe51d93df97ea17f994b370228635c7 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -1559,6 +1559,7 @@ 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;

diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index 1995dad59dd098893f7007dd6fee3c559a6d05c9..2db4a8b1542d37b2979eb105bb4a65f93f1de041 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -1775,6 +1775,7 @@ static void radeon_pm_compute_clocks_dpm(struct radeon_device *rdev)
        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;
@@ -1784,6 +1785,7 @@ static void radeon_pm_compute_clocks_dpm(struct radeon_device *rdev)
        /* 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) {
@@ -1791,6 +1793,12 @@ static void radeon_pm_compute_clocks_dpm(struct radeon_device *rdev)
                        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++;
                        }
                }
        }

diff --git a/drivers/gpu/drm/radeon/si_dpm.c b/drivers/gpu/drm/radeon/si_dpm.c
index 91bfc4762767b67c6828f751858514e35f116bf0..43b63705d0737f3b90458c5f5a1ac0b6910bb999 100644 (file)
--- a/drivers/gpu/drm/radeon/si_dpm.c
+++ b/drivers/gpu/drm/radeon/si_dpm.c
@@ -2979,6 +2979,9 @@ static void si_apply_state_adjust_rules(struct radeon_device *rdev,
                    (rdev->pdev->device == 0x6605)) {
                        max_sclk = 75000;
                }
+
+               if (rdev->pm.dpm.high_pixelclock_count > 1)
+                       disable_sclk_switching = true;
        }
 
        if (rps->vce_active) {