drm/radeon/dpm: implement vblank_too_short callback for cayman

Check if we can switch the mclk during the vblank time otherwise
we may get artifacts on the screen when the mclk changes.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

3 files changed, 17 insertions, 1 deletions

diff --git a/drivers/gpu/drm/radeon/ni_dpm.c b/drivers/gpu/drm/radeon/ni_dpm.c
index bd96eaa3f015..559cf24d51af 100644
--- a/drivers/gpu/drm/radeon/ni_dpm.c
+++ b/drivers/gpu/drm/radeon/ni_dpm.c
@@ -765,6 +765,19 @@ static void ni_calculate_leakage_for_v_and_t(struct radeon_device *rdev,
         ni_calculate_leakage_for_v_and_t_formula(coeff, v, t, i_leakage, leakage);
 }
 
+bool ni_dpm_vblank_too_short(struct radeon_device *rdev)
+{
+        struct rv7xx_power_info *pi = rv770_get_pi(rdev);
+        u32 vblank_time = r600_dpm_get_vblank_time(rdev);
+        u32 switch_limit = pi->mem_gddr5 ? 450 : 300;
+
+        if (vblank_time < switch_limit)
+                return true;
+        else
+                return false;
+
+}
+
 static void ni_apply_state_adjust_rules(struct radeon_device *rdev,
                                         struct radeon_ps *rps)
 {
@@ -775,7 +788,8 @@ static void ni_apply_state_adjust_rules(struct radeon_device *rdev,
         u16 vddc, vddci;
         int i;
 
-        if (rdev->pm.dpm.new_active_crtc_count > 1)
+        if ((rdev->pm.dpm.new_active_crtc_count > 1) ||
+            ni_dpm_vblank_too_short(rdev))
                 disable_mclk_switching = true;
         else
                 disable_mclk_switching = false;
diff --git a/drivers/gpu/drm/radeon/radeon_asic.c b/drivers/gpu/drm/radeon/radeon_asic.c
index c42b3674b426..c62428be9bed 100644
--- a/drivers/gpu/drm/radeon/radeon_asic.c
+++ b/drivers/gpu/drm/radeon/radeon_asic.c
@@ -1945,6 +1945,7 @@ static struct radeon_asic cayman_asic = {
                 .print_power_state = &ni_dpm_print_power_state,
                 .debugfs_print_current_performance_level = &ni_dpm_debugfs_print_current_performance_level,
                 .force_performance_level = &ni_dpm_force_performance_level,
+                .vblank_too_short = &ni_dpm_vblank_too_short,
         },
         .pflip = {
                 .pre_page_flip = &evergreen_pre_page_flip,
diff --git a/drivers/gpu/drm/radeon/radeon_asic.h b/drivers/gpu/drm/radeon/radeon_asic.h
index bca9a8bc062b..45d0693cddd5 100644
--- a/drivers/gpu/drm/radeon/radeon_asic.h
+++ b/drivers/gpu/drm/radeon/radeon_asic.h
@@ -624,6 +624,7 @@ void ni_dpm_debugfs_print_current_performance_level(struct radeon_device *rdev,
                                                     struct seq_file *m);
 int ni_dpm_force_performance_level(struct radeon_device *rdev,
                                    enum radeon_dpm_forced_level level);
+bool ni_dpm_vblank_too_short(struct radeon_device *rdev);
 int trinity_dpm_init(struct radeon_device *rdev);
 int trinity_dpm_enable(struct radeon_device *rdev);
 void trinity_dpm_disable(struct radeon_device *rdev);