drm/radeon/kms: add dynamic engine reclocking (V9)

V2: reorganize functions, fix modesetting calls
V3: rebase patch, use radeon's workqueue
V4: enable on tested chipsets only, request VBLANK IRQs
V5: enable PM on older hardware (IRQs, mode_fixup, dpms)
V6: use separate dynpm module parameter
V7: drop RADEON_ prefix, set minimum mode for dpms off
V8: update legacy encoder call, fix order in rs600 IRQ
V9: update compute_clocks call in legacy, not only DPMS_OFF

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_encoders.c b/drivers/gpu/drm/radeon/radeon_encoders.c
index c5ba1e3..f7d6078 100644
--- a/drivers/gpu/drm/radeon/radeon_encoders.c
+++ b/drivers/gpu/drm/radeon/radeon_encoders.c
@@ -262,6 +262,9 @@
 	struct drm_device *dev = encoder->dev;
 	struct radeon_device *rdev = dev->dev_private;
 
+	/* adjust pm to upcoming mode change */
+	radeon_pm_compute_clocks(rdev);
+
 	/* set the active encoder to connector routing */
 	radeon_encoder_set_active_device(encoder);
 	drm_mode_set_crtcinfo(adjusted_mode, 0);
@@ -1013,6 +1016,9 @@
 		atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
 	}
 	radeon_atombios_encoder_dpms_scratch_regs(encoder, (mode == DRM_MODE_DPMS_ON) ? true : false);
+
+	/* adjust pm to dpms change */
+	radeon_pm_compute_clocks(rdev);
 }
 
 union crtc_source_param {