[PATCH 3.16 085/217] drm/radeon: Don't drop DP 2.7 Ghz link setup on some cards.

From: Ben Hutchings
Date: Tue Apr 26 2016 - 19:26:11 EST


3.16.35-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Mario Kleiner <mario.kleiner.de@xxxxxxxxx>

commit 459ee1c3fd097ab56ababd8ff4bb7ef6a792de33 upstream.

As observed on Apple iMac10,1, DCE-3.2, RV-730,
link rate of 2.7 Ghz is not selected, because
the args.v1.ucConfig flag setting for 2.7 Ghz
gets overwritten by a following assignment of
the transmitter to use.

Move link rate setup a few lines down to fix this.
In practice this didn't have any positive or
negative effect on display setup on the tested
iMac10,1 so i don't know if backporting to stable
makes sense or not.

Signed-off-by: Mario Kleiner <mario.kleiner.de@xxxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/radeon/atombios_encoders.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@@ -896,8 +896,6 @@ atombios_dig_encoder_setup(struct drm_en
else
args.v1.ucLaneNum = 4;

- if (ENCODER_MODE_IS_DP(args.v1.ucEncoderMode) && (dp_clock == 270000))
- args.v1.ucConfig |= ATOM_ENCODER_CONFIG_DPLINKRATE_2_70GHZ;
switch (radeon_encoder->encoder_id) {
case ENCODER_OBJECT_ID_INTERNAL_UNIPHY:
args.v1.ucConfig = ATOM_ENCODER_CONFIG_V2_TRANSMITTER1;
@@ -914,6 +912,10 @@ atombios_dig_encoder_setup(struct drm_en
args.v1.ucConfig |= ATOM_ENCODER_CONFIG_LINKB;
else
args.v1.ucConfig |= ATOM_ENCODER_CONFIG_LINKA;
+
+ if (ENCODER_MODE_IS_DP(args.v1.ucEncoderMode) && (dp_clock == 270000))
+ args.v1.ucConfig |= ATOM_ENCODER_CONFIG_DPLINKRATE_2_70GHZ;
+
break;
case 2:
case 3: