From: Baihan Li <libai...@huawei.com>

DP Link training successful at 8.1Gbps with some monitors' max link rate
are 2.7Gbps. So change the default 8.1Gbps link rate to the rate that reads
from devices' capabilities.

Fixes: f9698f802e50 ("drm/hisilicon/hibmc: Restructuring the header dp_reg.h")
Signed-off-by: Baihan Li <libai...@huawei.com>
---
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h  |  4 ++-
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c    |  6 +---
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c  | 33 +++++++++++++------
 .../gpu/drm/hisilicon/hibmc/dp/dp_serdes.c    | 12 -------
 4 files changed, 27 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h 
b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
index 4add05c7f161..18a961466ff0 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
@@ -25,6 +25,9 @@ struct hibmc_link_status {
 struct hibmc_link_cap {
        u8 link_rate;
        u8 lanes;
+       int rx_dpcd_revision;
+       bool is_tps3;
+       bool is_tps4;
 };
 
 struct hibmc_dp_link {
@@ -62,7 +65,6 @@ struct hibmc_dp_dev {
 
 void hibmc_dp_aux_init(struct hibmc_dp *dp);
 int hibmc_dp_link_training(struct hibmc_dp_dev *dp);
-int hibmc_dp_serdes_init(struct hibmc_dp_dev *dp);
 int hibmc_dp_serdes_rate_switch(u8 rate, struct hibmc_dp_dev *dp);
 int hibmc_dp_serdes_set_tx_cfg(struct hibmc_dp_dev *dp, u8 
train_set[HIBMC_DP_LANE_NUM_MAX]);
 
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c 
b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
index 8f0daec7d174..ee0b543afd7f 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
@@ -154,7 +154,6 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
 {
        struct drm_device *drm_dev = dp->drm_dev;
        struct hibmc_dp_dev *dp_dev;
-       int ret;
 
        dp_dev = devm_kzalloc(drm_dev->dev, sizeof(struct hibmc_dp_dev), 
GFP_KERNEL);
        if (!dp_dev)
@@ -166,13 +165,10 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
 
        dp_dev->dev = drm_dev;
        dp_dev->base = dp->mmio + HIBMC_DP_OFFSET;
+       dp_dev->serdes_base = dp_dev->base + HIBMC_DP_HOST_OFFSET;
 
        hibmc_dp_aux_init(dp);
 
-       ret = hibmc_dp_serdes_init(dp_dev);
-       if (ret)
-               return ret;
-
        dp_dev->link.cap.lanes = 0x2;
        dp_dev->link.cap.link_rate = DP_LINK_BW_8_1;
 
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c 
b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
index 74f7832ea53e..6c69fa2ae9cf 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
@@ -39,6 +39,14 @@ static int hibmc_dp_link_training_configure(struct 
hibmc_dp_dev *dp)
        /* enhanced frame */
        hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_CTRL, 
HIBMC_DP_CFG_STREAM_FRAME_MODE, 0x1);
 
+       ret = hibmc_dp_get_serdes_rate_cfg(dp);
+       if (ret < 0)
+               return ret;
+
+       ret = hibmc_dp_serdes_rate_switch(ret, dp);
+       if (ret)
+               return ret;
+
        /* set rate and lane count */
        buf[0] = dp->link.cap.link_rate;
        buf[1] = DP_LANE_COUNT_ENHANCED_FRAME_EN | dp->link.cap.lanes;
@@ -325,6 +333,20 @@ static int hibmc_dp_link_downgrade_training_eq(struct 
hibmc_dp_dev *dp)
        return hibmc_dp_link_reduce_rate(dp);
 }
 
+static void hibmc_dp_update_caps(struct hibmc_dp_dev *dp)
+{
+       dp->link.cap.rx_dpcd_revision = dp->dpcd[DP_DPCD_REV];
+
+       dp->link.cap.is_tps3 = (dp->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_13) &&
+                              (dp->dpcd[DP_MAX_LANE_COUNT] & 
DP_TPS3_SUPPORTED);
+       dp->link.cap.is_tps4 = (dp->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) &&
+                              (dp->dpcd[DP_MAX_DOWNSPREAD] & 
DP_TPS4_SUPPORTED);
+       dp->link.cap.link_rate = dp->dpcd[DP_MAX_LINK_RATE];
+       dp->link.cap.lanes = dp->dpcd[DP_MAX_LANE_COUNT] & 
DP_MAX_LANE_COUNT_MASK;
+       if (dp->link.cap.lanes > HIBMC_DP_LANE_NUM_MAX)
+               dp->link.cap.lanes = HIBMC_DP_LANE_NUM_MAX;
+}
+
 int hibmc_dp_link_training(struct hibmc_dp_dev *dp)
 {
        struct hibmc_dp_link *link = &dp->link;
@@ -334,16 +356,7 @@ int hibmc_dp_link_training(struct hibmc_dp_dev *dp)
        if (ret)
                drm_err(dp->dev, "dp aux read dpcd failed, ret: %d\n", ret);
 
-       dp->link.cap.link_rate = dp->dpcd[DP_MAX_LINK_RATE];
-       dp->link.cap.lanes = 0x2;
-
-       ret = hibmc_dp_get_serdes_rate_cfg(dp);
-       if (ret < 0)
-               return ret;
-
-       ret = hibmc_dp_serdes_rate_switch(ret, dp);
-       if (ret)
-               return ret;
+       hibmc_dp_update_caps(dp);
 
        while (true) {
                ret = hibmc_dp_link_training_cr_pre(dp);
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_serdes.c 
b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_serdes.c
index 676059d4c1e6..8191233aa965 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_serdes.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_serdes.c
@@ -57,15 +57,3 @@ int hibmc_dp_serdes_rate_switch(u8 rate, struct hibmc_dp_dev 
*dp)
 
        return 0;
 }
-
-int hibmc_dp_serdes_init(struct hibmc_dp_dev *dp)
-{
-       dp->serdes_base = dp->base + HIBMC_DP_HOST_OFFSET;
-
-       writel(FIELD_PREP(HIBMC_DP_PMA_TXDEEMPH, DP_SERDES_VOL0_PRE0),
-              dp->serdes_base + HIBMC_DP_PMA_LANE0_OFFSET);
-       writel(FIELD_PREP(HIBMC_DP_PMA_TXDEEMPH, DP_SERDES_VOL0_PRE0),
-              dp->serdes_base + HIBMC_DP_PMA_LANE1_OFFSET);
-
-       return hibmc_dp_serdes_rate_switch(DP_SERDES_BW_8_1, dp);
-}
-- 
2.33.0

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