[PATCH] drm/radeon: fix eDP resume from suspend on iMac11, 1 / DCE3.1 systems

[Gilles Risch <gilles.risch@gmail.com>]

After suspend/resume the internal eDP display on iMac11,1 (and
potentially other DCE3.1 systems) stays dark because
atombios_set_edp_panel_power() skips panel power control for
anything older than DCE4.

Fix this by:
- Extending atombios_set_edp_panel_power() to also handle DCE3.1
  by changing the !ASIC_IS_DCE4() guard to !ASIC_IS_DCE31().
  HPD polling works correctly on DCE3.1 (verified: HPD is asserted
  at iteration 0 on iMac11,1).
- Issuing ATOM_ENCODER_CMD_DP_VIDEO_ON/OFF for DCE3.1 in addition
  to DCE4+.

Tested on iMac11,1 (Mobility Radeon HD 4850, RV770/DCE3.1).

Signed-off-by: Gilles Risch <gilles.risch@gmail.com>
---
 drivers/gpu/drm/radeon/atombios_encoders.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
index 4e984973c043..b62fd713efcf 100644
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -1383,7 +1383,7 @@ atombios_set_edp_panel_power(struct drm_connector *connector, int action)
 	if (connector->connector_type != DRM_MODE_CONNECTOR_eDP)
 		goto done;
 
-	if (!ASIC_IS_DCE4(rdev))
+	if (!ASIC_IS_DCE31(rdev))
 		goto done;
 
 	if ((action != ATOM_TRANSMITTER_ACTION_POWER_ON) &&
@@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 		if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
 			/* DP_SET_POWER_D0 is set in radeon_dp_link_train */
 			radeon_dp_link_train(encoder, connector);
-			if (ASIC_IS_DCE4(rdev))
+			if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev))
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
 		}
 		if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
@@ -1724,7 +1724,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 	case DRM_MODE_DPMS_SUSPEND:
 	case DRM_MODE_DPMS_OFF:
 
-		if (ASIC_IS_DCE4(rdev)) {
+		if (ASIC_IS_DCE4(rdev) || ASIC_IS_DCE31(rdev)) {
 			if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
 		}
-- 
2.47.3