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>
diff --git a/drivers/gpu/drm/radeon/ni_dpm.c b/drivers/gpu/drm/radeon/ni_dpm.c
index bd96eaa..559cf24 100644
--- a/drivers/gpu/drm/radeon/ni_dpm.c
+++ b/drivers/gpu/drm/radeon/ni_dpm.c
@@ -765,6 +765,19 @@
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 @@
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;