From: zain wang <wzz@rock-chips.com>
Date: Mon, 23 Apr 2018 12:49:45 +0200
Subject: drm/bridge: analogix_dp: Fix incorrect usage of enhanced mode
Git-commit: 1932250df1f0d6fe81fc785c5bb98f9474ae913e
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
Enhanced mode is required by the eDP 1.2 specification, and not doing it
early could result in a period of time where we have a link transmitting
idle packets without it. Since there is no reason to disable it, we just
enable it at the beginning of link training and then keep it on all the
time.
Cc: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: zain wang <wzz@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180423105003.9004-10-enric.balletbo@collabora.com
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -281,6 +281,8 @@ static int analogix_dp_link_start(struct
retval = drm_dp_dpcd_write(&dp->aux, DP_LINK_BW_SET, buf, 2);
if (retval < 0)
return retval;
+ /* set enhanced mode if available */
+ analogix_dp_set_enhanced_mode(dp);
/* Set TX pre-emphasis to minimum */
for (lane = 0; lane < lane_count; lane++)
@@ -593,8 +595,6 @@ static int analogix_dp_process_equalizer
dev_dbg(dp->dev, "fast link training %s\n",
dp->fast_train_enable ? "supported" : "unsupported");
- /* set enhanced mode if available */
- analogix_dp_set_enhanced_mode(dp);
dp->link_train.lt_state = FINISHED;
return 0;
@@ -940,8 +940,6 @@ static int analogix_dp_commit(struct ana
}
analogix_dp_enable_scramble(dp, 1);
- analogix_dp_enable_rx_to_enhanced_mode(dp, 1);
- analogix_dp_enable_enhanced_mode(dp, 1);
analogix_dp_init_video(dp);
ret = analogix_dp_config_video(dp);