[PATCH 01/21] drm/dp: Sort includes alphabetically

[PATCH 01/21] drm/dp: Sort includes alphabetically

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Keeping the list sorted alphabetically makes it much easier to determine
where to add new includes.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 include/drm/drm_dp_helper.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 8364502f92cf..114261158b73 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -23,9 +23,9 @@
 #ifndef _DRM_DP_HELPER_H_
 #define _DRM_DP_HELPER_H_
 
-#include <linux/types.h>
-#include <linux/i2c.h>
 #include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/types.h>
 
 /*
  * Unless otherwise noted, all values are from the DP 1.1a spec.  Note that
-- 
2.22.0

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[PATCH 02/21] drm/dp: Add missing kerneldoc for struct drm_dp_link

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

The drm_dp_link structure tracks capabilities on the DP link. Add some
kerneldoc to explain what each of its fields means.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 include/drm/drm_dp_helper.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 114261158b73..935f331e6e72 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1358,6 +1358,13 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
  */
 #define DP_LINK_CAP_ENHANCED_FRAMING (1 << 0)
 
+/**
+ * struct drm_dp_link - DP link capabilities
+ * @revision: DP specification revision supported on the link
+ * @rate: maximum clock rate supported on the link
+ * @num_lanes: maximum number of lanes supported on the link
+ * @capabilities: bitmask of capabilities supported on the link
+ */
 struct drm_dp_link {
 	unsigned char revision;
 	unsigned int rate;
-- 
2.22.0

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[PATCH 03/21] drm/dp: Add drm_dp_link_reset() implementation

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Subsequent patches will add non-volatile fields to struct drm_dp_link,
so introduce a function to zero out only the volatile fields.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index ffc68d305afe..f5af71ec1b7d 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -336,6 +336,17 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
 }
 EXPORT_SYMBOL(drm_dp_dpcd_read_link_status);
 
+static void drm_dp_link_reset(struct drm_dp_link *link)
+{
+	if (!link)
+		return;
+
+	link->revision = 0;
+	link->rate = 0;
+	link->num_lanes = 0;
+	link->capabilities = 0;
+}
+
 /**
  * drm_dp_link_probe() - probe a DisplayPort link for capabilities
  * @aux: DisplayPort AUX channel
@@ -352,7 +363,7 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	u8 values[3];
 	int err;
 
-	memset(link, 0, sizeof(*link));
+	drm_dp_link_reset(link);
 
 	err = drm_dp_dpcd_read(aux, DP_DPCD_REV, values, sizeof(values));
 	if (err < 0)
-- 
2.22.0

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[PATCH 04/21] drm/dp: Track link capabilities alongside settings

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Store capabilities in max_* fields and add separate fields for the
currently selected settings.

Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/bridge/tc358767.c      | 14 ++++++-------
 drivers/gpu/drm/drm_dp_helper.c        | 16 ++++++++++-----
 drivers/gpu/drm/msm/edp/edp_ctrl.c     |  8 ++++----
 drivers/gpu/drm/rockchip/cdn-dp-core.c |  8 ++++----
 drivers/gpu/drm/rockchip/cdn-dp-reg.c  | 13 ++++++------
 drivers/gpu/drm/tegra/dpaux.c          |  8 ++++----
 drivers/gpu/drm/tegra/sor.c            | 28 +++++++++++++-------------
 include/drm/drm_dp_helper.h            | 15 +++++++++-----
 8 files changed, 60 insertions(+), 50 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index 42f03a985ac0..a39036e89cf7 100644
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -437,7 +437,7 @@ static u32 tc_srcctrl(struct tc_data *tc)
 		reg |= DP0_SRCCTRL_SCRMBLDIS;	/* Scrambler Disabled */
 	if (tc->link.spread)
 		reg |= DP0_SRCCTRL_SSCG;	/* Spread Spectrum Enable */
-	if (tc->link.base.num_lanes == 2)
+	if (tc->link.base.lanes == 2)
 		reg |= DP0_SRCCTRL_LANES_2;	/* Two Main Channel Lanes */
 	if (tc->link.base.rate != 162000)
 		reg |= DP0_SRCCTRL_BW27;	/* 2.7 Gbps link */
@@ -674,9 +674,9 @@ static int tc_get_display_props(struct tc_data *tc)
 		tc->link.base.rate = 270000;
 	}
 
-	if (tc->link.base.num_lanes > 2) {
+	if (tc->link.base.lanes > 2) {
 		dev_dbg(tc->dev, "Falling to 2 lanes\n");
-		tc->link.base.num_lanes = 2;
+		tc->link.base.lanes = 2;
 	}
 
 	ret = drm_dp_dpcd_readb(&tc->aux, DP_MAX_DOWNSPREAD, &reg);
@@ -698,7 +698,7 @@ static int tc_get_display_props(struct tc_data *tc)
 	dev_dbg(tc->dev, "DPCD rev: %d.%d, rate: %s, lanes: %d, framing: %s\n",
 		tc->link.base.revision >> 4, tc->link.base.revision & 0x0f,
 		(tc->link.base.rate == 162000) ? "1.62Gbps" : "2.7Gbps",
-		tc->link.base.num_lanes,
+		tc->link.base.lanes,
 		(tc->link.base.capabilities & DP_LINK_CAP_ENHANCED_FRAMING) ?
 		"enhanced" : "non-enhanced");
 	dev_dbg(tc->dev, "Downspread: %s, scrambler: %s\n",
@@ -906,7 +906,7 @@ static int tc_main_link_enable(struct tc_data *tc)
 
 	/* Setup Main Link */
 	dp_phy_ctrl = BGREN | PWR_SW_EN | PHY_A0_EN | PHY_M0_EN;
-	if (tc->link.base.num_lanes == 2)
+	if (tc->link.base.lanes == 2)
 		dp_phy_ctrl |= PHY_2LANE;
 
 	ret = regmap_write(tc->regmap, DP_PHY_CTRL, dp_phy_ctrl);
@@ -1094,7 +1094,7 @@ static int tc_main_link_enable(struct tc_data *tc)
 		ret = -ENODEV;
 	}
 
-	if (tc->link.base.num_lanes == 2) {
+	if (tc->link.base.lanes == 2) {
 		value = (tmp[0] >> 4) & DP_CHANNEL_EQ_BITS;
 
 		if (value != DP_CHANNEL_EQ_BITS) {
@@ -1291,7 +1291,7 @@ static enum drm_mode_status tc_mode_valid(struct drm_bridge *bridge,
 		return MODE_CLOCK_HIGH;
 
 	req = mode->clock * bits_per_pixel / 8;
-	avail = tc->link.base.num_lanes * tc->link.base.rate;
+	avail = tc->link.base.lanes * tc->link.base.rate;
 
 	if (req > avail)
 		return MODE_BAD;
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index f5af71ec1b7d..365de63a02fb 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -342,9 +342,12 @@ static void drm_dp_link_reset(struct drm_dp_link *link)
 		return;
 
 	link->revision = 0;
-	link->rate = 0;
-	link->num_lanes = 0;
+	link->max_rate = 0;
+	link->max_lanes = 0;
 	link->capabilities = 0;
+
+	link->rate = 0;
+	link->lanes = 0;
 }
 
 /**
@@ -370,12 +373,15 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 		return err;
 
 	link->revision = values[0];
-	link->rate = drm_dp_bw_code_to_link_rate(values[1]);
-	link->num_lanes = values[2] & DP_MAX_LANE_COUNT_MASK;
+	link->max_rate = drm_dp_bw_code_to_link_rate(values[1]);
+	link->max_lanes = values[2] & DP_MAX_LANE_COUNT_MASK;
 
 	if (values[2] & DP_ENHANCED_FRAME_CAP)
 		link->capabilities |= DP_LINK_CAP_ENHANCED_FRAMING;
 
+	link->rate = link->max_rate;
+	link->lanes = link->max_lanes;
+
 	return 0;
 }
 EXPORT_SYMBOL(drm_dp_link_probe);
@@ -462,7 +468,7 @@ int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	int err;
 
 	values[0] = drm_dp_link_rate_to_bw_code(link->rate);
-	values[1] = link->num_lanes;
+	values[1] = link->lanes;
 
 	if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
 		values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
diff --git a/drivers/gpu/drm/msm/edp/edp_ctrl.c b/drivers/gpu/drm/msm/edp/edp_ctrl.c
index 7f3dd3ffe2c9..4b31bc30be2c 100644
--- a/drivers/gpu/drm/msm/edp/edp_ctrl.c
+++ b/drivers/gpu/drm/msm/edp/edp_ctrl.c
@@ -403,7 +403,7 @@ static void edp_fill_link_cfg(struct edp_ctrl *ctrl)
 	u32 prate;
 	u32 lrate;
 	u32 bpp;
-	u8 max_lane = ctrl->dp_link.num_lanes;
+	u8 max_lane = ctrl->dp_link.max_lanes;
 	u8 lane;
 
 	prate = ctrl->pixel_rate;
@@ -413,7 +413,7 @@ static void edp_fill_link_cfg(struct edp_ctrl *ctrl)
 	 * By default, use the maximum link rate and minimum lane count,
 	 * so that we can do rate down shift during link training.
 	 */
-	ctrl->link_rate = drm_dp_link_rate_to_bw_code(ctrl->dp_link.rate);
+	ctrl->link_rate = drm_dp_link_rate_to_bw_code(ctrl->dp_link.max_rate);
 
 	prate *= bpp;
 	prate /= 8; /* in kByte */
@@ -701,7 +701,7 @@ static int edp_link_rate_down_shift(struct edp_ctrl *ctrl)
 
 	rate = ctrl->link_rate;
 	lane = ctrl->lane_cnt;
-	max_lane = ctrl->dp_link.num_lanes;
+	max_lane = ctrl->dp_link.max_lanes;
 
 	bpp = ctrl->color_depth * 3;
 	prate = ctrl->pixel_rate;
@@ -759,7 +759,7 @@ static int edp_do_link_train(struct edp_ctrl *ctrl)
 	 * Set the current link rate and lane cnt to panel. They may have been
 	 * adjusted and the values are different from them in DPCD CAP
 	 */
-	dp_link.num_lanes = ctrl->lane_cnt;
+	dp_link.lanes = ctrl->lane_cnt;
 	dp_link.rate = drm_dp_bw_code_to_link_rate(ctrl->link_rate);
 	dp_link.capabilities = ctrl->dp_link.capabilities;
 	if (drm_dp_link_configure(ctrl->drm_aux, &dp_link) < 0)
diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
index d505ea7d5384..c500be895e64 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
@@ -478,7 +478,7 @@ static int cdn_dp_disable(struct cdn_dp_device *dp)
 	cdn_dp_clk_disable(dp);
 	dp->active = false;
 	dp->link.rate = 0;
-	dp->link.num_lanes = 0;
+	dp->link.lanes = 0;
 	if (!dp->connected) {
 		kfree(dp->edid);
 		dp->edid = NULL;
@@ -570,7 +570,7 @@ static bool cdn_dp_check_link_status(struct cdn_dp_device *dp)
 	struct cdn_dp_port *port = cdn_dp_connected_port(dp);
 	u8 sink_lanes = drm_dp_max_lane_count(dp->dpcd);
 
-	if (!port || !dp->link.rate || !dp->link.num_lanes)
+	if (!port || !dp->link.rate || !dp->link.lanes)
 		return false;
 
 	if (cdn_dp_dpcd_read(dp, DP_LANE0_1_STATUS, link_status,
@@ -953,7 +953,7 @@ static void cdn_dp_pd_event_work(struct work_struct *work)
 	/* Enabled and connected with a sink, re-train if requested */
 	} else if (!cdn_dp_check_link_status(dp)) {
 		unsigned int rate = dp->link.rate;
-		unsigned int lanes = dp->link.num_lanes;
+		unsigned int lanes = dp->link.lanes;
 		struct drm_display_mode *mode = &dp->mode;
 
 		DRM_DEV_INFO(dp->dev, "Connected with sink. Re-train link\n");
@@ -966,7 +966,7 @@ static void cdn_dp_pd_event_work(struct work_struct *work)
 
 		/* If training result is changed, update the video config */
 		if (mode->clock &&
-		    (rate != dp->link.rate || lanes != dp->link.num_lanes)) {
+		    (rate != dp->link.rate || lanes != dp->link.lanes)) {
 			ret = cdn_dp_config_video(dp);
 			if (ret) {
 				dp->connected = false;
diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.c b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
index 077c87021908..7b254d0d0ba2 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-reg.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
@@ -536,7 +536,7 @@ static int cdn_dp_get_training_status(struct cdn_dp_device *dp)
 		goto err_get_training_status;
 
 	dp->link.rate = drm_dp_bw_code_to_link_rate(status[0]);
-	dp->link.num_lanes = status[1];
+	dp->link.lanes = status[1];
 
 err_get_training_status:
 	if (ret)
@@ -561,7 +561,7 @@ int cdn_dp_train_link(struct cdn_dp_device *dp)
 	}
 
 	DRM_DEV_DEBUG_KMS(dp->dev, "rate:0x%x, lanes:%d\n", dp->link.rate,
-			  dp->link.num_lanes);
+			  dp->link.lanes);
 	return ret;
 }
 
@@ -659,14 +659,13 @@ int cdn_dp_config_video(struct cdn_dp_device *dp)
 	do {
 		tu_size_reg += 2;
 		symbol = tu_size_reg * mode->clock * bit_per_pix;
-		do_div(symbol, dp->link.num_lanes * link_rate * 8);
+		do_div(symbol, dp->link.lanes * link_rate * 8);
 		rem = do_div(symbol, 1000);
 		if (tu_size_reg > 64) {
 			ret = -EINVAL;
 			DRM_DEV_ERROR(dp->dev,
 				      "tu error, clk:%d, lanes:%d, rate:%d\n",
-				      mode->clock, dp->link.num_lanes,
-				      link_rate);
+				      mode->clock, dp->link.lanes, link_rate);
 			goto err_config_video;
 		}
 	} while ((symbol <= 1) || (tu_size_reg - symbol < 4) ||
@@ -680,7 +679,7 @@ int cdn_dp_config_video(struct cdn_dp_device *dp)
 
 	/* set the FIFO Buffer size */
 	val = div_u64(mode->clock * (symbol + 1), 1000) + link_rate;
-	val /= (dp->link.num_lanes * link_rate);
+	val /= (dp->link.lanes * link_rate);
 	val = div_u64(8 * (symbol + 1), bit_per_pix) - val;
 	val += 2;
 	ret = cdn_dp_reg_write(dp, DP_VC_TABLE(15), val);
@@ -833,7 +832,7 @@ static void cdn_dp_audio_config_i2s(struct cdn_dp_device *dp,
 	u32 val;
 
 	if (audio->channels == 2) {
-		if (dp->link.num_lanes == 1)
+		if (dp->link.lanes == 1)
 			sub_pckt_num = 2;
 		else
 			sub_pckt_num = 4;
diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
index 2d94da225e51..c186167b0b3f 100644
--- a/drivers/gpu/drm/tegra/dpaux.c
+++ b/drivers/gpu/drm/tegra/dpaux.c
@@ -791,14 +791,14 @@ int drm_dp_aux_train(struct drm_dp_aux *aux, struct drm_dp_link *link,
 	if (tp == DP_TRAINING_PATTERN_DISABLE)
 		return 0;
 
-	for (i = 0; i < link->num_lanes; i++)
+	for (i = 0; i < link->lanes; i++)
 		values[i] = DP_TRAIN_MAX_PRE_EMPHASIS_REACHED |
 			    DP_TRAIN_PRE_EMPH_LEVEL_0 |
 			    DP_TRAIN_MAX_SWING_REACHED |
 			    DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
 
 	err = drm_dp_dpcd_write(aux, DP_TRAINING_LANE0_SET, values,
-				link->num_lanes);
+				link->lanes);
 	if (err < 0)
 		return err;
 
@@ -810,13 +810,13 @@ int drm_dp_aux_train(struct drm_dp_aux *aux, struct drm_dp_link *link,
 
 	switch (tp) {
 	case DP_TRAINING_PATTERN_1:
-		if (!drm_dp_clock_recovery_ok(status, link->num_lanes))
+		if (!drm_dp_clock_recovery_ok(status, link->lanes))
 			return -EAGAIN;
 
 		break;
 
 	case DP_TRAINING_PATTERN_2:
-		if (!drm_dp_channel_eq_ok(status, link->num_lanes))
+		if (!drm_dp_channel_eq_ok(status, link->lanes))
 			return -EAGAIN;
 
 		break;
diff --git a/drivers/gpu/drm/tegra/sor.c b/drivers/gpu/drm/tegra/sor.c
index 4ffe3794e6d3..7b795162d7b3 100644
--- a/drivers/gpu/drm/tegra/sor.c
+++ b/drivers/gpu/drm/tegra/sor.c
@@ -646,7 +646,7 @@ static int tegra_sor_dp_train_fast(struct tegra_sor *sor,
 	if (err < 0)
 		return err;
 
-	for (i = 0, value = 0; i < link->num_lanes; i++) {
+	for (i = 0, value = 0; i < link->lanes; i++) {
 		unsigned long lane = SOR_DP_TPG_CHANNEL_CODING |
 				     SOR_DP_TPG_SCRAMBLER_NONE |
 				     SOR_DP_TPG_PATTERN_TRAIN1;
@@ -667,7 +667,7 @@ static int tegra_sor_dp_train_fast(struct tegra_sor *sor,
 	value |= SOR_DP_SPARE_MACRO_SOR_CLK;
 	tegra_sor_writel(sor, value, SOR_DP_SPARE0);
 
-	for (i = 0, value = 0; i < link->num_lanes; i++) {
+	for (i = 0, value = 0; i < link->lanes; i++) {
 		unsigned long lane = SOR_DP_TPG_CHANNEL_CODING |
 				     SOR_DP_TPG_SCRAMBLER_NONE |
 				     SOR_DP_TPG_PATTERN_TRAIN2;
@@ -682,7 +682,7 @@ static int tegra_sor_dp_train_fast(struct tegra_sor *sor,
 	if (err < 0)
 		return err;
 
-	for (i = 0, value = 0; i < link->num_lanes; i++) {
+	for (i = 0, value = 0; i < link->lanes; i++) {
 		unsigned long lane = SOR_DP_TPG_CHANNEL_CODING |
 				     SOR_DP_TPG_SCRAMBLER_GALIOS |
 				     SOR_DP_TPG_PATTERN_NONE;
@@ -909,11 +909,11 @@ static int tegra_sor_compute_config(struct tegra_sor *sor,
 	u32 num_syms_per_line;
 	unsigned int i;
 
-	if (!link_rate || !link->num_lanes || !pclk || !config->bits_per_pixel)
+	if (!link_rate || !link->lanes || !pclk || !config->bits_per_pixel)
 		return -EINVAL;
 
-	output = link_rate * 8 * link->num_lanes;
 	input = pclk * config->bits_per_pixel;
+	output = link_rate * 8 * link->lanes;
 
 	if (input >= output)
 		return -ERANGE;
@@ -956,7 +956,7 @@ static int tegra_sor_compute_config(struct tegra_sor *sor,
 	watermark = div_u64(watermark + params.error, f);
 	config->watermark = watermark + (config->bits_per_pixel / 8) + 2;
 	num_syms_per_line = (mode->hdisplay * config->bits_per_pixel) *
-			    (link->num_lanes * 8);
+			    (link->lanes * 8);
 
 	if (config->watermark > 30) {
 		config->watermark = 30;
@@ -976,12 +976,12 @@ static int tegra_sor_compute_config(struct tegra_sor *sor,
 	if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
 		config->hblank_symbols -= 3;
 
-	config->hblank_symbols -= 12 / link->num_lanes;
+	config->hblank_symbols -= 12 / link->lanes;
 
 	/* compute the number of symbols per vertical blanking interval */
 	num = (mode->hdisplay - 25) * link_rate;
 	config->vblank_symbols = div_u64(num, pclk);
-	config->vblank_symbols -= 36 / link->num_lanes + 4;
+	config->vblank_symbols -= 36 / link->lanes + 4;
 
 	dev_dbg(sor->dev, "blank symbols: H:%u V:%u\n", config->hblank_symbols,
 		config->vblank_symbols);
@@ -1827,17 +1827,17 @@ static void tegra_sor_edp_enable(struct drm_encoder *encoder)
 	/* power DP lanes */
 	value = tegra_sor_readl(sor, sor->soc->regs->dp_padctl0);
 
-	if (link.num_lanes <= 2)
+	if (link.lanes <= 2)
 		value &= ~(SOR_DP_PADCTL_PD_TXD_3 | SOR_DP_PADCTL_PD_TXD_2);
 	else
 		value |= SOR_DP_PADCTL_PD_TXD_3 | SOR_DP_PADCTL_PD_TXD_2;
 
-	if (link.num_lanes <= 1)
+	if (link.lanes <= 1)
 		value &= ~SOR_DP_PADCTL_PD_TXD_1;
 	else
 		value |= SOR_DP_PADCTL_PD_TXD_1;
 
-	if (link.num_lanes == 0)
+	if (link.lanes == 0)
 		value &= ~SOR_DP_PADCTL_PD_TXD_0;
 	else
 		value |= SOR_DP_PADCTL_PD_TXD_0;
@@ -1846,7 +1846,7 @@ static void tegra_sor_edp_enable(struct drm_encoder *encoder)
 
 	value = tegra_sor_readl(sor, SOR_DP_LINKCTL0);
 	value &= ~SOR_DP_LINKCTL_LANE_COUNT_MASK;
-	value |= SOR_DP_LINKCTL_LANE_COUNT(link.num_lanes);
+	value |= SOR_DP_LINKCTL_LANE_COUNT(link.lanes);
 	tegra_sor_writel(sor, value, SOR_DP_LINKCTL0);
 
 	/* start lane sequencer */
@@ -1903,7 +1903,7 @@ static void tegra_sor_edp_enable(struct drm_encoder *encoder)
 		dev_err(sor->dev, "failed to configure eDP link: %d\n", err);
 
 	rate = drm_dp_link_rate_to_bw_code(link.rate);
-	lanes = link.num_lanes;
+	lanes = link.lanes;
 
 	value = tegra_sor_readl(sor, SOR_CLK_CNTRL);
 	value &= ~SOR_CLK_CNTRL_DP_LINK_SPEED_MASK;
@@ -1921,7 +1921,7 @@ static void tegra_sor_edp_enable(struct drm_encoder *encoder)
 
 	/* disable training pattern generator */
 
-	for (i = 0; i < link.num_lanes; i++) {
+	for (i = 0; i < link.lanes; i++) {
 		unsigned long lane = SOR_DP_TPG_CHANNEL_CODING |
 				     SOR_DP_TPG_SCRAMBLER_GALIOS |
 				     SOR_DP_TPG_PATTERN_NONE;
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 935f331e6e72..9c675bde11e8 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1359,17 +1359,22 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
 #define DP_LINK_CAP_ENHANCED_FRAMING (1 << 0)
 
 /**
- * struct drm_dp_link - DP link capabilities
+ * struct drm_dp_link - DP link capabilities and configuration
  * @revision: DP specification revision supported on the link
- * @rate: maximum clock rate supported on the link
- * @num_lanes: maximum number of lanes supported on the link
+ * @max_rate: maximum clock rate supported on the link
+ * @max_lanes: maximum number of lanes supported on the link
  * @capabilities: bitmask of capabilities supported on the link
+ * @rate: currently configured link rate
+ * @lanes: currently configured number of lanes
  */
 struct drm_dp_link {
 	unsigned char revision;
-	unsigned int rate;
-	unsigned int num_lanes;
+	unsigned int max_rate;
+	unsigned int max_lanes;
 	unsigned long capabilities;
+
+	unsigned int rate;
+	unsigned int lanes;
 };
 
 int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link);
-- 
2.22.0

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[PATCH 05/21] drm/dp: Turn link capabilities into booleans

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Rather than storing capabilities as flags in an integer, use a separate
boolean per capability. This simplifies the code that checks for these
capabilities.

Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/bridge/tc358767.c  |  9 ++++-----
 drivers/gpu/drm/drm_dp_helper.c    | 19 ++++++++++++++++---
 drivers/gpu/drm/msm/edp/edp_ctrl.c |  4 ++--
 drivers/gpu/drm/tegra/sor.c        |  4 ++--
 include/drm/drm_dp_helper.h        | 17 ++++++++++++++---
 5 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index a39036e89cf7..1bbfcc5534ab 100644
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -699,8 +699,8 @@ static int tc_get_display_props(struct tc_data *tc)
 		tc->link.base.revision >> 4, tc->link.base.revision & 0x0f,
 		(tc->link.base.rate == 162000) ? "1.62Gbps" : "2.7Gbps",
 		tc->link.base.lanes,
-		(tc->link.base.capabilities & DP_LINK_CAP_ENHANCED_FRAMING) ?
-		"enhanced" : "non-enhanced");
+		tc->link.base.caps.enhanced_framing ? "enhanced" :
+			"non-enhanced");
 	dev_dbg(tc->dev, "Downspread: %s, scrambler: %s\n",
 		tc->link.spread ? "0.5%" : "0.0%",
 		tc->link.scrambler_dis ? "disabled" : "enabled");
@@ -1013,8 +1013,7 @@ static int tc_main_link_enable(struct tc_data *tc)
 
 	/* Enable DP0 to start Link Training */
 	ret = regmap_write(tc->regmap, DP0CTL,
-			   ((tc->link.base.capabilities &
-			     DP_LINK_CAP_ENHANCED_FRAMING) ? EF_EN : 0) |
+			   (tc->link.base.caps.enhanced_framing ? EF_EN : 0) |
 			   DP_EN);
 	if (ret)
 		return ret;
@@ -1165,7 +1164,7 @@ static int tc_stream_enable(struct tc_data *tc)
 		return ret;
 
 	value = VID_MN_GEN | DP_EN;
-	if (tc->link.base.capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
+	if (tc->link.base.caps.enhanced_framing)
 		value |= EF_EN;
 	ret = regmap_write(tc->regmap, DP0CTL, value);
 	if (ret)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 365de63a02fb..bdf999bb6cfa 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -336,6 +336,18 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
 }
 EXPORT_SYMBOL(drm_dp_dpcd_read_link_status);
 
+static void drm_dp_link_caps_reset(struct drm_dp_link_caps *caps)
+{
+	caps->enhanced_framing = false;
+}
+
+void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
+			   const struct drm_dp_link_caps *src)
+{
+	dest->enhanced_framing = src->enhanced_framing;
+}
+EXPORT_SYMBOL(drm_dp_link_caps_copy);
+
 static void drm_dp_link_reset(struct drm_dp_link *link)
 {
 	if (!link)
@@ -344,7 +356,8 @@ static void drm_dp_link_reset(struct drm_dp_link *link)
 	link->revision = 0;
 	link->max_rate = 0;
 	link->max_lanes = 0;
-	link->capabilities = 0;
+
+	drm_dp_link_caps_reset(&link->caps);
 
 	link->rate = 0;
 	link->lanes = 0;
@@ -377,7 +390,7 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	link->max_lanes = values[2] & DP_MAX_LANE_COUNT_MASK;
 
 	if (values[2] & DP_ENHANCED_FRAME_CAP)
-		link->capabilities |= DP_LINK_CAP_ENHANCED_FRAMING;
+		link->caps.enhanced_framing = true;
 
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
@@ -470,7 +483,7 @@ int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	values[0] = drm_dp_link_rate_to_bw_code(link->rate);
 	values[1] = link->lanes;
 
-	if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
+	if (link->caps.enhanced_framing)
 		values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
 
 	err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, values, sizeof(values));
diff --git a/drivers/gpu/drm/msm/edp/edp_ctrl.c b/drivers/gpu/drm/msm/edp/edp_ctrl.c
index 4b31bc30be2c..0a6c77e791aa 100644
--- a/drivers/gpu/drm/msm/edp/edp_ctrl.c
+++ b/drivers/gpu/drm/msm/edp/edp_ctrl.c
@@ -439,7 +439,7 @@ static void edp_config_ctrl(struct edp_ctrl *ctrl)
 
 	data = EDP_CONFIGURATION_CTRL_LANES(ctrl->lane_cnt - 1);
 
-	if (ctrl->dp_link.capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
+	if (ctrl->dp_link.caps.enhanced_framing)
 		data |= EDP_CONFIGURATION_CTRL_ENHANCED_FRAMING;
 
 	depth = EDP_6BIT;
@@ -761,7 +761,7 @@ static int edp_do_link_train(struct edp_ctrl *ctrl)
 	 */
 	dp_link.lanes = ctrl->lane_cnt;
 	dp_link.rate = drm_dp_bw_code_to_link_rate(ctrl->link_rate);
-	dp_link.capabilities = ctrl->dp_link.capabilities;
+	drm_dp_link_caps_copy(&dp_link.caps, &ctrl->dp_link.caps);
 	if (drm_dp_link_configure(ctrl->drm_aux, &dp_link) < 0)
 		return EDP_TRAIN_FAIL;
 
diff --git a/drivers/gpu/drm/tegra/sor.c b/drivers/gpu/drm/tegra/sor.c
index 7b795162d7b3..f7947e023514 100644
--- a/drivers/gpu/drm/tegra/sor.c
+++ b/drivers/gpu/drm/tegra/sor.c
@@ -973,7 +973,7 @@ static int tegra_sor_compute_config(struct tegra_sor *sor,
 	num = ((mode->htotal - mode->hdisplay) - 7) * link_rate;
 	config->hblank_symbols = div_u64(num, pclk);
 
-	if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
+	if (link->caps.enhanced_framing)
 		config->hblank_symbols -= 3;
 
 	config->hblank_symbols -= 12 / link->lanes;
@@ -1914,7 +1914,7 @@ static void tegra_sor_edp_enable(struct drm_encoder *encoder)
 	value &= ~SOR_DP_LINKCTL_LANE_COUNT_MASK;
 	value |= SOR_DP_LINKCTL_LANE_COUNT(lanes);
 
-	if (link.capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
+	if (link.caps.enhanced_framing)
 		value |= SOR_DP_LINKCTL_ENHANCED_FRAME;
 
 	tegra_sor_writel(sor, value, SOR_DP_LINKCTL0);
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 9c675bde11e8..2759f8d7e90d 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1356,14 +1356,24 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
 /*
  * DisplayPort link
  */
-#define DP_LINK_CAP_ENHANCED_FRAMING (1 << 0)
+
+/**
+ * struct drm_dp_link_caps - DP link capabilities
+ * @enhanced_framing: enhanced framing capability (mandatory as of DP 1.2)
+ */
+struct drm_dp_link_caps {
+	bool enhanced_framing;
+};
+
+void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
+			   const struct drm_dp_link_caps *src);
 
 /**
  * struct drm_dp_link - DP link capabilities and configuration
  * @revision: DP specification revision supported on the link
  * @max_rate: maximum clock rate supported on the link
  * @max_lanes: maximum number of lanes supported on the link
- * @capabilities: bitmask of capabilities supported on the link
+ * @caps: capabilities supported on the link (see &drm_dp_link_caps)
  * @rate: currently configured link rate
  * @lanes: currently configured number of lanes
  */
@@ -1371,7 +1381,8 @@ struct drm_dp_link {
 	unsigned char revision;
 	unsigned int max_rate;
 	unsigned int max_lanes;
-	unsigned long capabilities;
+
+	struct drm_dp_link_caps caps;
 
 	unsigned int rate;
 	unsigned int lanes;
-- 
2.22.0

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[PATCH 06/21] drm/dp: Probe link using existing parsing helpers

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Use existing parsing helpers to probe a DisplayPort link.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 29 ++++++++++++++++++++++-------
 include/drm/drm_dp_helper.h     |  2 ++
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index bdf999bb6cfa..cdf49e8d5e3a 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -320,6 +320,22 @@ ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
 }
 EXPORT_SYMBOL(drm_dp_dpcd_write);
 
+/**
+ * drm_dp_dpcd_read_link_caps() - read DPCD link capabilities
+ * @aux: DisplayPort AUX channel
+ * @caps: buffer to store the link capabilities in
+ *
+ * Returns:
+ * The number of bytes transferred on success or a negative error code on
+ * failure.
+ */
+int drm_dp_dpcd_read_link_caps(struct drm_dp_aux *aux,
+			       u8 caps[DP_RECEIVER_CAP_SIZE])
+{
+	return drm_dp_dpcd_read(aux, DP_DPCD_REV, caps, DP_RECEIVER_CAP_SIZE);
+}
+EXPORT_SYMBOL(drm_dp_dpcd_read_link_caps);
+
 /**
  * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207)
  * @aux: DisplayPort AUX channel
@@ -376,21 +392,20 @@ static void drm_dp_link_reset(struct drm_dp_link *link)
  */
 int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 {
-	u8 values[3];
+	u8 values[DP_RECEIVER_CAP_SIZE];
 	int err;
 
 	drm_dp_link_reset(link);
 
-	err = drm_dp_dpcd_read(aux, DP_DPCD_REV, values, sizeof(values));
+	err = drm_dp_dpcd_read_link_caps(aux, values);
 	if (err < 0)
 		return err;
 
-	link->revision = values[0];
-	link->max_rate = drm_dp_bw_code_to_link_rate(values[1]);
-	link->max_lanes = values[2] & DP_MAX_LANE_COUNT_MASK;
+	link->revision = values[DP_DPCD_REV];
+	link->max_rate = drm_dp_max_link_rate(values);
+	link->max_lanes = drm_dp_max_lane_count(values);
 
-	if (values[2] & DP_ENHANCED_FRAME_CAP)
-		link->caps.enhanced_framing = true;
+	link->caps.enhanced_framing = drm_dp_enhanced_frame_cap(values);
 
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 2759f8d7e90d..60bb030c858d 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1350,6 +1350,8 @@ static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
 	return drm_dp_dpcd_write(aux, offset, &value, 1);
 }
 
+int drm_dp_dpcd_read_link_caps(struct drm_dp_aux *aux,
+			       u8 caps[DP_RECEIVER_CAP_SIZE]);
 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
 				 u8 status[DP_LINK_STATUS_SIZE]);
 
-- 
2.22.0

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[PATCH 07/21] drm/dp: Read fast training capability from link

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

While probing the DisplayPort link, query the fast training capability.
If supported, drivers can use the fast link training sequence instead of
the more involved full link training sequence.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 3 +++
 include/drm/drm_dp_helper.h     | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index cdf49e8d5e3a..74e4fceace7e 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -355,12 +355,14 @@ EXPORT_SYMBOL(drm_dp_dpcd_read_link_status);
 static void drm_dp_link_caps_reset(struct drm_dp_link_caps *caps)
 {
 	caps->enhanced_framing = false;
+	caps->fast_training = false;
 }
 
 void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
 			   const struct drm_dp_link_caps *src)
 {
 	dest->enhanced_framing = src->enhanced_framing;
+	dest->fast_training = src->fast_training;
 }
 EXPORT_SYMBOL(drm_dp_link_caps_copy);
 
@@ -406,6 +408,7 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	link->max_lanes = drm_dp_max_lane_count(values);
 
 	link->caps.enhanced_framing = drm_dp_enhanced_frame_cap(values);
+	link->caps.fast_training = drm_dp_fast_training_cap(values);
 
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 60bb030c858d..c148f5685195 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1143,6 +1143,13 @@ drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 		(dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
 }
 
+static inline bool
+drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DPCD_REV] >= 0x11 &&
+		(dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
+}
+
 static inline bool
 drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 {
@@ -1362,9 +1369,11 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
 /**
  * struct drm_dp_link_caps - DP link capabilities
  * @enhanced_framing: enhanced framing capability (mandatory as of DP 1.2)
+ * @fast_training: AUX CH handshake not required for link training
  */
 struct drm_dp_link_caps {
 	bool enhanced_framing;
+	bool fast_training;
 };
 
 void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
-- 
2.22.0

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[PATCH 08/21] drm/dp: Read TPS3 capability from sink

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

The TPS3 capability can be exposed by DP 1.2 and later sinks if they
support the alternative training pattern for channel equalization.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 3 +++
 include/drm/drm_dp_helper.h     | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 74e4fceace7e..c47d78973c1e 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -355,6 +355,7 @@ EXPORT_SYMBOL(drm_dp_dpcd_read_link_status);
 static void drm_dp_link_caps_reset(struct drm_dp_link_caps *caps)
 {
 	caps->enhanced_framing = false;
+	caps->tps3_supported = false;
 	caps->fast_training = false;
 }
 
@@ -362,6 +363,7 @@ void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
 			   const struct drm_dp_link_caps *src)
 {
 	dest->enhanced_framing = src->enhanced_framing;
+	dest->tps3_supported = src->tps3_supported;
 	dest->fast_training = src->fast_training;
 }
 EXPORT_SYMBOL(drm_dp_link_caps_copy);
@@ -408,6 +410,7 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	link->max_lanes = drm_dp_max_lane_count(values);
 
 	link->caps.enhanced_framing = drm_dp_enhanced_frame_cap(values);
+	link->caps.tps3_supported = drm_dp_tps3_supported(values);
 	link->caps.fast_training = drm_dp_fast_training_cap(values);
 
 	link->rate = link->max_rate;
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index c148f5685195..ab98ebb302a9 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1369,10 +1369,12 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
 /**
  * struct drm_dp_link_caps - DP link capabilities
  * @enhanced_framing: enhanced framing capability (mandatory as of DP 1.2)
+ * @tps3_supported: training pattern sequence 3 supported for equalization
  * @fast_training: AUX CH handshake not required for link training
  */
 struct drm_dp_link_caps {
 	bool enhanced_framing;
+	bool tps3_supported;
 	bool fast_training;
 };
 
-- 
2.22.0

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[PATCH 09/21] drm/dp: Read channel coding capability from sink

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Parse from the sink capabilities whether or not it supports ANSI 8B/10B
channel coding as specified in ANSI X3.230-1994, clause 11.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 3 +++
 include/drm/drm_dp_helper.h     | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index c47d78973c1e..1c238196c8b4 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -357,6 +357,7 @@ static void drm_dp_link_caps_reset(struct drm_dp_link_caps *caps)
 	caps->enhanced_framing = false;
 	caps->tps3_supported = false;
 	caps->fast_training = false;
+	caps->channel_coding = false;
 }
 
 void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
@@ -365,6 +366,7 @@ void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
 	dest->enhanced_framing = src->enhanced_framing;
 	dest->tps3_supported = src->tps3_supported;
 	dest->fast_training = src->fast_training;
+	dest->channel_coding = src->channel_coding;
 }
 EXPORT_SYMBOL(drm_dp_link_caps_copy);
 
@@ -412,6 +414,7 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	link->caps.enhanced_framing = drm_dp_enhanced_frame_cap(values);
 	link->caps.tps3_supported = drm_dp_tps3_supported(values);
 	link->caps.fast_training = drm_dp_fast_training_cap(values);
+	link->caps.channel_coding = drm_dp_channel_coding_supported(values);
 
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index ab98ebb302a9..d144d3a54dbc 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -95,6 +95,7 @@
 # define DP_DETAILED_CAP_INFO_AVAILABLE	    (1 << 4) /* DPI */
 
 #define DP_MAIN_LINK_CHANNEL_CODING         0x006
+# define DP_CAP_ANSI_8B10B		    (1 << 0)
 
 #define DP_DOWN_STREAM_PORT_COUNT	    0x007
 # define DP_PORT_COUNT_MASK		    0x0f
@@ -1215,6 +1216,12 @@ drm_dp_sink_supports_fec(const u8 fec_capable)
 	return fec_capable & DP_FEC_CAPABLE;
 }
 
+static inline bool
+drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
+}
+
 /*
  * DisplayPort AUX channel
  */
@@ -1371,11 +1378,13 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
  * @enhanced_framing: enhanced framing capability (mandatory as of DP 1.2)
  * @tps3_supported: training pattern sequence 3 supported for equalization
  * @fast_training: AUX CH handshake not required for link training
+ * @channel_coding: ANSI 8B/10B channel coding capability
  */
 struct drm_dp_link_caps {
 	bool enhanced_framing;
 	bool tps3_supported;
 	bool fast_training;
+	bool channel_coding;
 };
 
 void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
-- 
2.22.0

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[PATCH 10/21] drm/dp: Read alternate scrambler reset capability from sink

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Parse from the sink capabilities whether or not the eDP alternate
scrambler reset value of 0xfffe is supported.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 5 +++++
 include/drm/drm_dp_helper.h     | 9 +++++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 1c238196c8b4..acab8dc48e2c 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -358,6 +358,7 @@ static void drm_dp_link_caps_reset(struct drm_dp_link_caps *caps)
 	caps->tps3_supported = false;
 	caps->fast_training = false;
 	caps->channel_coding = false;
+	caps->alternate_scrambler_reset = false;
 }
 
 void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
@@ -367,6 +368,7 @@ void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
 	dest->tps3_supported = src->tps3_supported;
 	dest->fast_training = src->fast_training;
 	dest->channel_coding = src->channel_coding;
+	dest->alternate_scrambler_reset = src->alternate_scrambler_reset;
 }
 EXPORT_SYMBOL(drm_dp_link_caps_copy);
 
@@ -416,6 +418,9 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	link->caps.fast_training = drm_dp_fast_training_cap(values);
 	link->caps.channel_coding = drm_dp_channel_coding_supported(values);
 
+	if (drm_dp_alternate_scrambler_reset_cap(values))
+		link->caps.alternate_scrambler_reset = true;
+
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
 
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index d144d3a54dbc..f9f65bc13df5 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1222,6 +1222,13 @@ drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 	return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
 }
 
+static inline bool
+drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_EDP_CONFIGURATION_CAP] &
+			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
+}
+
 /*
  * DisplayPort AUX channel
  */
@@ -1379,12 +1386,14 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
  * @tps3_supported: training pattern sequence 3 supported for equalization
  * @fast_training: AUX CH handshake not required for link training
  * @channel_coding: ANSI 8B/10B channel coding capability
+ * @alternate_scrambler_reset: eDP alternate scrambler reset capability
  */
 struct drm_dp_link_caps {
 	bool enhanced_framing;
 	bool tps3_supported;
 	bool fast_training;
 	bool channel_coding;
+	bool alternate_scrambler_reset;
 };
 
 void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
-- 
2.22.0

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[PATCH 11/21] drm/dp: Read eDP version from DPCD

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

If the sink supports eDP, read the eDP revision from it's DPCD.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 16 +++++++++++++++-
 include/drm/drm_dp_helper.h     |  2 ++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index acab8dc48e2c..5b36e8e39ca7 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -382,6 +382,7 @@ static void drm_dp_link_reset(struct drm_dp_link *link)
 	link->max_lanes = 0;
 
 	drm_dp_link_caps_reset(&link->caps);
+	link->edp = 0;
 
 	link->rate = 0;
 	link->lanes = 0;
@@ -418,9 +419,22 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	link->caps.fast_training = drm_dp_fast_training_cap(values);
 	link->caps.channel_coding = drm_dp_channel_coding_supported(values);
 
-	if (drm_dp_alternate_scrambler_reset_cap(values))
+	if (drm_dp_alternate_scrambler_reset_cap(values)) {
+		static const u8 edp_revs[] = { 0x11, 0x12, 0x13, 0x14 };
+		u8 value;
+
 		link->caps.alternate_scrambler_reset = true;
 
+		err = drm_dp_dpcd_readb(aux, DP_EDP_DPCD_REV, &value);
+		if (err < 0)
+			return err;
+
+		if (value >= ARRAY_SIZE(edp_revs))
+			DRM_ERROR("unsupported eDP version: %02x\n", value);
+		else
+			link->edp = edp_revs[value];
+	}
+
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
 
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index f9f65bc13df5..13c50e905205 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1405,6 +1405,7 @@ void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
  * @max_rate: maximum clock rate supported on the link
  * @max_lanes: maximum number of lanes supported on the link
  * @caps: capabilities supported on the link (see &drm_dp_link_caps)
+ * @edp: eDP revision (0x11: eDP 1.1, 0x12: eDP 1.2, ...)
  * @rate: currently configured link rate
  * @lanes: currently configured number of lanes
  */
@@ -1414,6 +1415,7 @@ struct drm_dp_link {
 	unsigned int max_lanes;
 
 	struct drm_dp_link_caps caps;
+	unsigned char edp;
 
 	unsigned int rate;
 	unsigned int lanes;
-- 
2.22.0

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[PATCH 12/21] drm/dp: Read AUX read interval from DPCD

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Store the AUX read interval from DPCD, so that it can be used to wait
for the durations given in the specification during link training.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c |  3 +++
 include/drm/drm_dp_helper.h     | 35 +++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 5b36e8e39ca7..4112570dbe67 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -382,6 +382,7 @@ static void drm_dp_link_reset(struct drm_dp_link *link)
 	link->max_lanes = 0;
 
 	drm_dp_link_caps_reset(&link->caps);
+	link->aux_rd_interval = 0;
 	link->edp = 0;
 
 	link->rate = 0;
@@ -435,6 +436,8 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 			link->edp = edp_revs[value];
 	}
 
+	link->aux_rd_interval = drm_dp_aux_rd_interval(values);
+
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
 
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 13c50e905205..fcfd2b19d5bd 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -25,8 +25,11 @@
 
 #include <linux/delay.h>
 #include <linux/i2c.h>
+#include <linux/time64.h>
 #include <linux/types.h>
 
+#include <drm/drm_print.h>
+
 /*
  * Unless otherwise noted, all values are from the DP 1.1a spec.  Note that
  * DP and DPCD versions are independent.  Differences from 1.0 are not noted,
@@ -1229,6 +1232,36 @@ drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 			DP_ALTERNATE_SCRAMBLER_RESET_CAP;
 }
 
+/**
+ * drm_dp_read_aux_interval() - read the AUX read interval from the DPCD
+ * @dpcd: receiver capacity buffer
+ *
+ * Reads the AUX read interval (in microseconds) from the DPCD. Note that the
+ * TRAINING_AUX_RD_INTERVAL stores the value in units of 4 milliseconds. If no
+ * read interval is specified and for DPCD v1.4 and later, the read interval
+ * is always 100 microseconds.
+ *
+ * Returns:
+ * The read AUX interval in microseconds.
+ */
+static inline unsigned int
+drm_dp_aux_rd_interval(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
+					DP_TRAINING_AUX_RD_MASK;
+
+	if (rd_interval > 4)
+		DRM_DEBUG_KMS("AUX interval %u, out of range (max: 4)\n",
+			      rd_interval);
+
+	if (rd_interval > 0 && dpcd[DP_DPCD_REV] < DP_DPCD_REV_14)
+		rd_interval *= 4 * MSEC_PER_SEC;
+	else
+		rd_interval = 100;
+
+	return rd_interval;
+}
+
 /*
  * DisplayPort AUX channel
  */
@@ -1405,6 +1438,7 @@ void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
  * @max_rate: maximum clock rate supported on the link
  * @max_lanes: maximum number of lanes supported on the link
  * @caps: capabilities supported on the link (see &drm_dp_link_caps)
+ * @aux_rd_interval: AUX read interval to use for training (in microseconds)
  * @edp: eDP revision (0x11: eDP 1.1, 0x12: eDP 1.2, ...)
  * @rate: currently configured link rate
  * @lanes: currently configured number of lanes
@@ -1415,6 +1449,7 @@ struct drm_dp_link {
 	unsigned int max_lanes;
 
 	struct drm_dp_link_caps caps;
+	unsigned int aux_rd_interval;
 	unsigned char edp;
 
 	unsigned int rate;
-- 
2.22.0

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[PATCH 13/21] drm/dp: Do not busy-loop during link training

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Use microsecond sleeps for the clock recovery and channel equalization
delays during link training. The duration of these delays can be from
100 us up to 16 ms. It is rude to busy-loop for that amount of time.

While at it, also convert to standard coding style by putting the
opening braces in a function definition on a new line.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 4112570dbe67..344f887fef2c 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -120,33 +120,39 @@ u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SI
 }
 EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
 
-void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) {
-	int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
-			  DP_TRAINING_AUX_RD_MASK;
+void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
+					DP_TRAINING_AUX_RD_MASK;
 
 	if (rd_interval > 4)
-		DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n",
+		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
 			      rd_interval);
 
 	if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
-		udelay(100);
+		rd_interval = 100;
 	else
-		mdelay(rd_interval * 4);
+		rd_interval *= 4;
+
+	usleep_range(rd_interval, rd_interval * 2);
 }
 EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
 
-void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) {
-	int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
-			  DP_TRAINING_AUX_RD_MASK;
+void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
+					DP_TRAINING_AUX_RD_MASK;
 
 	if (rd_interval > 4)
-		DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n",
+		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
 			      rd_interval);
 
 	if (rd_interval == 0)
-		udelay(400);
+		rd_interval = 400;
 	else
-		mdelay(rd_interval * 4);
+		rd_interval *= 4;
+
+	usleep_range(rd_interval, rd_interval * 2);
 }
 EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
 
-- 
2.22.0

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[PATCH 14/21] drm/dp: Use drm_dp_aux_rd_interval()

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Make use of the newly added drm_dp_aux_rd_interval() helper in existing
DP link training helpers and add comments about minimum required delays
mandated by the DP specification.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 26 +++-----------------------
 1 file changed, 3 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 344f887fef2c..1fb3c27cd012 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -122,17 +122,7 @@ EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
 
 void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 {
-	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
-					DP_TRAINING_AUX_RD_MASK;
-
-	if (rd_interval > 4)
-		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
-			      rd_interval);
-
-	if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
-		rd_interval = 100;
-	else
-		rd_interval *= 4;
+	unsigned int rd_interval = drm_dp_aux_rd_interval(dpcd);
 
 	usleep_range(rd_interval, rd_interval * 2);
 }
@@ -140,19 +130,9 @@ EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
 
 void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 {
-	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
-					DP_TRAINING_AUX_RD_MASK;
-
-	if (rd_interval > 4)
-		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
-			      rd_interval);
+	unsigned int min = drm_dp_aux_rd_interval(dpcd);
 
-	if (rd_interval == 0)
-		rd_interval = 400;
-	else
-		rd_interval *= 4;
-
-	usleep_range(rd_interval, rd_interval * 2);
+	usleep_range(min, min * 2);
 }
 EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
 
-- 
2.22.0

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[PATCH 15/21] drm/dp: Add helper to get post-cursor adjustments

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

If the transmitter supports pre-emphasis post cursor2 the sink will
request adjustments in a similar way to how it requests adjustments to
the voltage swing and pre-emphasis settings.

Add a helper to extract these adjustments on a per-lane basis from the
DPCD link status.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 10 ++++++++++
 include/drm/drm_dp_helper.h     | 10 ++++++++++
 2 files changed, 20 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 1fb3c27cd012..f1f3705fade9 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -120,6 +120,16 @@ u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SI
 }
 EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
 
+u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZE],
+					 unsigned int lane)
+{
+	unsigned int offset = DP_ADJUST_REQUEST_POST_CURSOR2;
+	u8 value = dp_link_status(link_status, offset);
+
+	return (value >> (lane << 1)) & 0x3;
+}
+EXPORT_SYMBOL(drm_dp_get_adjust_request_post_cursor);
+
 void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 {
 	unsigned int rd_interval = drm_dp_aux_rd_interval(dpcd);
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index fcfd2b19d5bd..cd728b8a4dee 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -566,6 +566,14 @@
 # define DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT  6
 
 #define DP_ADJUST_REQUEST_POST_CURSOR2      0x20c
+# define DP_ADJUST_POST_CURSOR2_LANE0_MASK  0x03
+# define DP_ADJUST_POST_CURSOR2_LANE0_SHIFT 0
+# define DP_ADJUST_POST_CURSOR2_LANE1_MASK  0x0c
+# define DP_ADJUST_POST_CURSOR2_LANE1_SHIFT 2
+# define DP_ADJUST_POST_CURSOR2_LANE2_MASK  0x30
+# define DP_ADJUST_POST_CURSOR2_LANE2_SHIFT 4
+# define DP_ADJUST_POST_CURSOR2_LANE3_MASK  0xc0
+# define DP_ADJUST_POST_CURSOR2_LANE3_SHIFT 6
 
 #define DP_TEST_REQUEST			    0x218
 # define DP_TEST_LINK_TRAINING		    (1 << 0)
@@ -1053,6 +1061,8 @@ u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
 				     int lane);
 u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
 					  int lane);
+u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZE],
+					 unsigned int lane);
 
 #define DP_BRANCH_OUI_HEADER_SIZE	0xc
 #define DP_RECEIVER_CAP_SIZE		0xf
-- 
2.22.0

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[PATCH 16/21] drm/dp: Set channel coding on link configuration

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Make use of ANSI 8B/10B channel coding if the DisplayPort sink supports
it.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index f1f3705fade9..f51a5595ebc0 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -519,7 +519,7 @@ EXPORT_SYMBOL(drm_dp_link_power_down);
  */
 int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)
 {
-	u8 values[2];
+	u8 values[2], value = 0;
 	int err;
 
 	values[0] = drm_dp_link_rate_to_bw_code(link->rate);
@@ -532,6 +532,13 @@ int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	if (err < 0)
 		return err;
 
+	if (link->caps.channel_coding)
+		value = DP_SET_ANSI_8B10B;
+
+	err = drm_dp_dpcd_writeb(aux, DP_MAIN_LINK_CHANNEL_CODING_SET, value);
+	if (err < 0)
+		return err;
+
 	return 0;
 }
 EXPORT_SYMBOL(drm_dp_link_configure);
-- 
2.22.0

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[PATCH 17/21] drm/dp: Enable alternate scrambler reset when supported

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

If the sink is eDP and supports the alternate scrambler reset, enable
it.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index f51a5595ebc0..85956f3a24e3 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -539,6 +539,13 @@ int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	if (err < 0)
 		return err;
 
+	if (link->caps.alternate_scrambler_reset) {
+		err = drm_dp_dpcd_writeb(aux, DP_EDP_CONFIGURATION_SET,
+					 DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
+		if (err < 0)
+			return err;
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL(drm_dp_link_configure);
-- 
2.22.0

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[PATCH 18/21] drm/dp: Add drm_dp_link_choose() helper

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

This helper chooses an appropriate configuration, according to the
bitrate requirements of the video mode and the capabilities of the
DisplayPort sink.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 55 +++++++++++++++++++++++++++++++++
 include/drm/drm_dp_helper.h     |  4 +++
 2 files changed, 59 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 85956f3a24e3..01d34f33c658 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -550,6 +550,61 @@ int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)
 }
 EXPORT_SYMBOL(drm_dp_link_configure);
 
+/**
+ * drm_dp_link_choose() - choose the lowest possible configuration for a mode
+ * @link: DRM DP link object
+ * @mode: DRM display mode
+ * @info: DRM display information
+ *
+ * According to the eDP specification, a source should select a configuration
+ * with the lowest number of lanes and the lowest possible link rate that can
+ * match the bitrate requirements of a video mode. However it must ensure not
+ * to exceed the capabilities of the sink.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int drm_dp_link_choose(struct drm_dp_link *link,
+		       const struct drm_display_mode *mode,
+		       const struct drm_display_info *info)
+{
+	/* available link symbol clock rates */
+	static const unsigned int rates[3] = { 162000, 270000, 540000 };
+	/* available number of lanes */
+	static const unsigned int lanes[3] = { 1, 2, 4 };
+	unsigned long requirement, capacity;
+	unsigned int rate = link->max_rate;
+	unsigned int i, j;
+
+	/* bandwidth requirement */
+	requirement = mode->clock * info->bpc * 3;
+
+	for (i = 0; i < ARRAY_SIZE(lanes) && lanes[i] <= link->max_lanes; i++) {
+		for (j = 0; j < ARRAY_SIZE(rates) && rates[j] <= rate; j++) {
+			/*
+			 * Capacity for this combination of lanes and rate,
+			 * factoring in the ANSI 8B/10B encoding.
+			 *
+			 * Link rates in the DRM DP helpers are really link
+			 * symbol frequencies, so a tenth of the actual rate
+			 * of the link.
+			 */
+			capacity = lanes[i] * (rates[j] * 10) * 8 / 10;
+
+			if (capacity >= requirement) {
+				DRM_DEBUG_KMS("using %u lanes at %u kHz (%lu/%lu kbps)\n",
+					      lanes[i], rates[j], requirement,
+					      capacity);
+				link->lanes = lanes[i];
+				link->rate = rates[j];
+				return 0;
+			}
+		}
+	}
+
+	return -ERANGE;
+}
+EXPORT_SYMBOL(drm_dp_link_choose);
+
 /**
  * drm_dp_downstream_max_clock() - extract branch device max
  *                                 pixel rate for legacy VGA
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index cd728b8a4dee..0f256458a57d 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -28,6 +28,7 @@
 #include <linux/time64.h>
 #include <linux/types.h>
 
+#include <drm/drm_crtc.h>
 #include <drm/drm_print.h>
 
 /*
@@ -1470,6 +1471,9 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link);
 int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link);
 int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link);
 int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link);
+int drm_dp_link_choose(struct drm_dp_link *link,
+		       const struct drm_display_mode *mode,
+		       const struct drm_display_info *info);
 int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
 				const u8 port_cap[4]);
 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
-- 
2.22.0

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[PATCH 19/21] drm/dp: Add support for eDP link rates

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 121 ++++++++++++++++++++++++++++++++
 include/drm/drm_dp_helper.h     |   9 +++
 2 files changed, 130 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 01d34f33c658..136ee609f2ee 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -385,6 +385,107 @@ static void drm_dp_link_reset(struct drm_dp_link *link)
 	link->lanes = 0;
 }
 
+/**
+ * drm_dp_link_add_rate() - add a rate to the list of supported rates
+ * @link: the link to add the rate to
+ * @rate: the rate to add
+ *
+ * Add a link rate to the list of supported link rates.
+ *
+ * Returns:
+ * 0 on success or one of the following negative error codes on failure:
+ * - ENOSPC if the maximum number of supported rates has been reached
+ * - EEXISTS if the link already supports this rate
+ *
+ * See also:
+ * drm_dp_link_remove_rate()
+ */
+int drm_dp_link_add_rate(struct drm_dp_link *link, unsigned long rate)
+{
+	unsigned int i, pivot;
+
+	if (link->num_rates == DP_MAX_SUPPORTED_RATES)
+		return -ENOSPC;
+
+	for (pivot = 0; pivot < link->num_rates; pivot++)
+		if (rate <= link->rates[pivot])
+			break;
+
+	if (pivot != link->num_rates && rate == link->rates[pivot])
+		return -EEXIST;
+
+	for (i = link->num_rates; i > pivot; i--)
+		link->rates[i] = link->rates[i - 1];
+
+	link->rates[pivot] = rate;
+	link->num_rates++;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_link_add_rate);
+
+/**
+ * drm_dp_link_remove_rate() - remove a rate from the list of supported rates
+ * @link: the link from which to remove the rate
+ * @rate: the rate to remove
+ *
+ * Removes a link rate from the list of supported link rates.
+ *
+ * Returns:
+ * 0 on success or one of the following negative error codes on failure:
+ * - EINVAL if the specified rate is not among the supported rates
+ *
+ * See also:
+ * drm_dp_link_add_rate()
+ */
+int drm_dp_link_remove_rate(struct drm_dp_link *link, unsigned long rate)
+{
+	unsigned int i;
+
+	for (i = 0; i < link->num_rates; i++)
+		if (rate == link->rates[i])
+			break;
+
+	if (i == link->num_rates)
+		return -EINVAL;
+
+	link->num_rates--;
+
+	for (i = i; i < link->num_rates; i++)
+		link->rates[i] = link->rates[i + 1];
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_link_remove_rate);
+
+/**
+ * drm_dp_link_update_rates() - normalize the supported link rates array
+ * @link: the link for which to normalize the supported link rates
+ *
+ * Users should call this function after they've manually modified the array
+ * of supported link rates. This function removes any stale entries, compacts
+ * the array and updates the supported link rate count. Note that calling the
+ * drm_dp_link_remove_rate() function already does this janitorial work.
+ *
+ * See also:
+ * drm_dp_link_add_rate(), drm_dp_link_remove_rate()
+ */
+void drm_dp_link_update_rates(struct drm_dp_link *link)
+{
+	unsigned int i, count = 0;
+
+	for (i = 0; i < link->num_rates; i++) {
+		if (link->rates[i] != 0)
+			link->rates[count++] = link->rates[i];
+	}
+
+	for (i = count; i < link->num_rates; i++)
+		link->rates[i] = 0;
+
+	link->num_rates = count;
+}
+EXPORT_SYMBOL(drm_dp_link_update_rates);
+
 /**
  * drm_dp_link_probe() - probe a DisplayPort link for capabilities
  * @aux: DisplayPort AUX channel
@@ -437,6 +538,26 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
 
+	/* Parse SUPPORTED_LINK_RATES from eDP 1.4 */
+	if (link->edp >= 0x14) {
+		u8 supported_rates[DP_MAX_SUPPORTED_RATES * 2];
+		unsigned int i;
+		u16 rate;
+
+		err = drm_dp_dpcd_read(aux, DP_SUPPORTED_LINK_RATES,
+				       supported_rates,
+				       sizeof(supported_rates));
+		if (err < 0)
+			return err;
+
+		for (i = 0; i < DP_MAX_SUPPORTED_RATES; i++) {
+			rate = supported_rates[i * 2 + 1] << 8 |
+			       supported_rates[i * 2 + 0];
+
+			drm_dp_link_add_rate(link, rate * 200);
+		}
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL(drm_dp_link_probe);
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 0f256458a57d..dd3076a835ef 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1453,6 +1453,8 @@ void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
  * @edp: eDP revision (0x11: eDP 1.1, 0x12: eDP 1.2, ...)
  * @rate: currently configured link rate
  * @lanes: currently configured number of lanes
+ * @rates: additional supported link rates in kHz (eDP 1.4)
+ * @num_rates: number of additional supported link rates (eDP 1.4)
  */
 struct drm_dp_link {
 	unsigned char revision;
@@ -1465,8 +1467,15 @@ struct drm_dp_link {
 
 	unsigned int rate;
 	unsigned int lanes;
+
+	unsigned long rates[DP_MAX_SUPPORTED_RATES];
+	unsigned int num_rates;
 };
 
+int drm_dp_link_add_rate(struct drm_dp_link *link, unsigned long rate);
+int drm_dp_link_remove_rate(struct drm_dp_link *link, unsigned long rate);
+void drm_dp_link_update_rates(struct drm_dp_link *link);
+
 int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link);
 int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link);
 int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link);
-- 
2.22.0

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[PATCH 20/21] drm/dp: Fix a couple of whitespace issues

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Remove a gratuituous blank line in one place and add a blank line in
another to improve readability.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 136ee609f2ee..6b4431bade3e 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -216,7 +216,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
 		}
 
 		ret = aux->transfer(aux, &msg);
-
 		if (ret >= 0) {
 			native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK;
 			if (native_reply == DP_AUX_NATIVE_REPLY_ACK) {
-- 
2.22.0

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[PATCH 21/21] drm/bridge: tc358767: Use DP nomenclature

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

The DP specification uses the term "default framing" instead of "non-
enhanced framing".

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/bridge/tc358767.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index 1bbfcc5534ab..c779fe6427f6 100644
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -699,8 +699,7 @@ static int tc_get_display_props(struct tc_data *tc)
 		tc->link.base.revision >> 4, tc->link.base.revision & 0x0f,
 		(tc->link.base.rate == 162000) ? "1.62Gbps" : "2.7Gbps",
 		tc->link.base.lanes,
-		tc->link.base.caps.enhanced_framing ? "enhanced" :
-			"non-enhanced");
+		tc->link.base.caps.enhanced_framing ? "enhanced" : "default");
 	dev_dbg(tc->dev, "Downspread: %s, scrambler: %s\n",
 		tc->link.spread ? "0.5%" : "0.0%",
 		tc->link.scrambler_dis ? "disabled" : "enabled");
-- 
2.22.0

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Re: [PATCH 04/21] drm/dp: Track link capabilities alongside settings

[Andrzej Hajda]

On 05.08.2019 14:23, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
>
> Store capabilities in max_* fields and add separate fields for the
> currently selected settings.
>
> Cc: Rob Clark <robdclark@gmail.com>
> Signed-off-by: Thierry Reding <treding@nvidia.com>


For bridge and core part:

Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>

 --
Regards
Andrzej


> ---
>  drivers/gpu/drm/bridge/tc358767.c      | 14 ++++++-------
>  drivers/gpu/drm/drm_dp_helper.c        | 16 ++++++++++-----
>  drivers/gpu/drm/msm/edp/edp_ctrl.c     |  8 ++++----
>  drivers/gpu/drm/rockchip/cdn-dp-core.c |  8 ++++----
>  drivers/gpu/drm/rockchip/cdn-dp-reg.c  | 13 ++++++------
>  drivers/gpu/drm/tegra/dpaux.c          |  8 ++++----
>  drivers/gpu/drm/tegra/sor.c            | 28 +++++++++++++-------------
>  include/drm/drm_dp_helper.h            | 15 +++++++++-----
>  8 files changed, 60 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
> index 42f03a985ac0..a39036e89cf7 100644
> --- a/drivers/gpu/drm/bridge/tc358767.c
> +++ b/drivers/gpu/drm/bridge/tc358767.c
> @@ -437,7 +437,7 @@ static u32 tc_srcctrl(struct tc_data *tc)
>  		reg |= DP0_SRCCTRL_SCRMBLDIS;	/* Scrambler Disabled */
>  	if (tc->link.spread)
>  		reg |= DP0_SRCCTRL_SSCG;	/* Spread Spectrum Enable */
> -	if (tc->link.base.num_lanes == 2)
> +	if (tc->link.base.lanes == 2)
>  		reg |= DP0_SRCCTRL_LANES_2;	/* Two Main Channel Lanes */
>  	if (tc->link.base.rate != 162000)
>  		reg |= DP0_SRCCTRL_BW27;	/* 2.7 Gbps link */
> @@ -674,9 +674,9 @@ static int tc_get_display_props(struct tc_data *tc)
>  		tc->link.base.rate = 270000;
>  	}
>  
> -	if (tc->link.base.num_lanes > 2) {
> +	if (tc->link.base.lanes > 2) {
>  		dev_dbg(tc->dev, "Falling to 2 lanes\n");
> -		tc->link.base.num_lanes = 2;
> +		tc->link.base.lanes = 2;
>  	}
>  
>  	ret = drm_dp_dpcd_readb(&tc->aux, DP_MAX_DOWNSPREAD, &reg);
> @@ -698,7 +698,7 @@ static int tc_get_display_props(struct tc_data *tc)
>  	dev_dbg(tc->dev, "DPCD rev: %d.%d, rate: %s, lanes: %d, framing: %s\n",
>  		tc->link.base.revision >> 4, tc->link.base.revision & 0x0f,
>  		(tc->link.base.rate == 162000) ? "1.62Gbps" : "2.7Gbps",
> -		tc->link.base.num_lanes,
> +		tc->link.base.lanes,
>  		(tc->link.base.capabilities & DP_LINK_CAP_ENHANCED_FRAMING) ?
>  		"enhanced" : "non-enhanced");
>  	dev_dbg(tc->dev, "Downspread: %s, scrambler: %s\n",
> @@ -906,7 +906,7 @@ static int tc_main_link_enable(struct tc_data *tc)
>  
>  	/* Setup Main Link */
>  	dp_phy_ctrl = BGREN | PWR_SW_EN | PHY_A0_EN | PHY_M0_EN;
> -	if (tc->link.base.num_lanes == 2)
> +	if (tc->link.base.lanes == 2)
>  		dp_phy_ctrl |= PHY_2LANE;
>  
>  	ret = regmap_write(tc->regmap, DP_PHY_CTRL, dp_phy_ctrl);
> @@ -1094,7 +1094,7 @@ static int tc_main_link_enable(struct tc_data *tc)
>  		ret = -ENODEV;
>  	}
>  
> -	if (tc->link.base.num_lanes == 2) {
> +	if (tc->link.base.lanes == 2) {
>  		value = (tmp[0] >> 4) & DP_CHANNEL_EQ_BITS;
>  
>  		if (value != DP_CHANNEL_EQ_BITS) {
> @@ -1291,7 +1291,7 @@ static enum drm_mode_status tc_mode_valid(struct drm_bridge *bridge,
>  		return MODE_CLOCK_HIGH;
>  
>  	req = mode->clock * bits_per_pixel / 8;
> -	avail = tc->link.base.num_lanes * tc->link.base.rate;
> +	avail = tc->link.base.lanes * tc->link.base.rate;
>  
>  	if (req > avail)
>  		return MODE_BAD;
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index f5af71ec1b7d..365de63a02fb 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -342,9 +342,12 @@ static void drm_dp_link_reset(struct drm_dp_link *link)
>  		return;
>  
>  	link->revision = 0;
> -	link->rate = 0;
> -	link->num_lanes = 0;
> +	link->max_rate = 0;
> +	link->max_lanes = 0;
>  	link->capabilities = 0;
> +
> +	link->rate = 0;
> +	link->lanes = 0;
>  }
>  
>  /**
> @@ -370,12 +373,15 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
>  		return err;
>  
>  	link->revision = values[0];
> -	link->rate = drm_dp_bw_code_to_link_rate(values[1]);
> -	link->num_lanes = values[2] & DP_MAX_LANE_COUNT_MASK;
> +	link->max_rate = drm_dp_bw_code_to_link_rate(values[1]);
> +	link->max_lanes = values[2] & DP_MAX_LANE_COUNT_MASK;
>  
>  	if (values[2] & DP_ENHANCED_FRAME_CAP)
>  		link->capabilities |= DP_LINK_CAP_ENHANCED_FRAMING;
>  
> +	link->rate = link->max_rate;
> +	link->lanes = link->max_lanes;
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL(drm_dp_link_probe);
> @@ -462,7 +468,7 @@ int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)
>  	int err;
>  
>  	values[0] = drm_dp_link_rate_to_bw_code(link->rate);
> -	values[1] = link->num_lanes;
> +	values[1] = link->lanes;
>  
>  	if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
>  		values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;

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Re: [PATCH 05/21] drm/dp: Turn link capabilities into booleans

[Andrzej Hajda]

On 05.08.2019 14:23, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
>
> Rather than storing capabilities as flags in an integer, use a separate
> boolean per capability. This simplifies the code that checks for these
> capabilities.
>
> Cc: Rob Clark <robdclark@gmail.com>
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/gpu/drm/bridge/tc358767.c  |  9 ++++-----
>  drivers/gpu/drm/drm_dp_helper.c    | 19 ++++++++++++++++---
>  drivers/gpu/drm/msm/edp/edp_ctrl.c |  4 ++--
>  drivers/gpu/drm/tegra/sor.c        |  4 ++--
>  include/drm/drm_dp_helper.h        | 17 ++++++++++++++---
>  5 files changed, 38 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
> index a39036e89cf7..1bbfcc5534ab 100644
> --- a/drivers/gpu/drm/bridge/tc358767.c
> +++ b/drivers/gpu/drm/bridge/tc358767.c
> @@ -699,8 +699,8 @@ static int tc_get_display_props(struct tc_data *tc)
>  		tc->link.base.revision >> 4, tc->link.base.revision & 0x0f,
>  		(tc->link.base.rate == 162000) ? "1.62Gbps" : "2.7Gbps",
>  		tc->link.base.lanes,
> -		(tc->link.base.capabilities & DP_LINK_CAP_ENHANCED_FRAMING) ?
> -		"enhanced" : "non-enhanced");
> +		tc->link.base.caps.enhanced_framing ? "enhanced" :
> +			"non-enhanced");
>  	dev_dbg(tc->dev, "Downspread: %s, scrambler: %s\n",
>  		tc->link.spread ? "0.5%" : "0.0%",
>  		tc->link.scrambler_dis ? "disabled" : "enabled");
> @@ -1013,8 +1013,7 @@ static int tc_main_link_enable(struct tc_data *tc)
>  
>  	/* Enable DP0 to start Link Training */
>  	ret = regmap_write(tc->regmap, DP0CTL,
> -			   ((tc->link.base.capabilities &
> -			     DP_LINK_CAP_ENHANCED_FRAMING) ? EF_EN : 0) |
> +			   (tc->link.base.caps.enhanced_framing ? EF_EN : 0) |
>  			   DP_EN);
>  	if (ret)
>  		return ret;
> @@ -1165,7 +1164,7 @@ static int tc_stream_enable(struct tc_data *tc)
>  		return ret;
>  
>  	value = VID_MN_GEN | DP_EN;
> -	if (tc->link.base.capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
> +	if (tc->link.base.caps.enhanced_framing)
>  		value |= EF_EN;
>  	ret = regmap_write(tc->regmap, DP0CTL, value);
>  	if (ret)
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 365de63a02fb..bdf999bb6cfa 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -336,6 +336,18 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
>  }
>  EXPORT_SYMBOL(drm_dp_dpcd_read_link_status);
>  
> +static void drm_dp_link_caps_reset(struct drm_dp_link_caps *caps)
> +{
> +	caps->enhanced_framing = false;
> +}
> +
> +void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
> +			   const struct drm_dp_link_caps *src)
> +{
> +	dest->enhanced_framing = src->enhanced_framing;
> +}
> +EXPORT_SYMBOL(drm_dp_link_caps_copy);


Probably this could be replaced by direct assignment:

*dest = *src;


> +
>  static void drm_dp_link_reset(struct drm_dp_link *link)
>  {
>  	if (!link)
> @@ -344,7 +356,8 @@ static void drm_dp_link_reset(struct drm_dp_link *link)
>  	link->revision = 0;
>  	link->max_rate = 0;
>  	link->max_lanes = 0;
> -	link->capabilities = 0;
> +
> +	drm_dp_link_caps_reset(&link->caps);
>  
>  	link->rate = 0;
>  	link->lanes = 0;
> @@ -377,7 +390,7 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
>  	link->max_lanes = values[2] & DP_MAX_LANE_COUNT_MASK;
>  
>  	if (values[2] & DP_ENHANCED_FRAME_CAP)
> -		link->capabilities |= DP_LINK_CAP_ENHANCED_FRAMING;
> +		link->caps.enhanced_framing = true;
>  
>  	link->rate = link->max_rate;
>  	link->lanes = link->max_lanes;
> @@ -470,7 +483,7 @@ int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)
>  	values[0] = drm_dp_link_rate_to_bw_code(link->rate);
>  	values[1] = link->lanes;
>  
> -	if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
> +	if (link->caps.enhanced_framing)
>  		values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
>  
>  	err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, values, sizeof(values));


Anyway for bridge and core part:

Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>

 --
Regards
Andrzej




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Re: [PATCH 21/21] drm/bridge: tc358767: Use DP nomenclature

[Andrzej Hajda]

On 05.08.2019 14:23, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
>
> The DP specification uses the term "default framing" instead of "non-
> enhanced framing".
>
> Signed-off-by: Thierry Reding <treding@nvidia.com>

Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>

 --
Regards
Andrzej

> ---
>  drivers/gpu/drm/bridge/tc358767.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
> index 1bbfcc5534ab..c779fe6427f6 100644
> --- a/drivers/gpu/drm/bridge/tc358767.c
> +++ b/drivers/gpu/drm/bridge/tc358767.c
> @@ -699,8 +699,7 @@ static int tc_get_display_props(struct tc_data *tc)
>  		tc->link.base.revision >> 4, tc->link.base.revision & 0x0f,
>  		(tc->link.base.rate == 162000) ? "1.62Gbps" : "2.7Gbps",
>  		tc->link.base.lanes,
> -		tc->link.base.caps.enhanced_framing ? "enhanced" :
> -			"non-enhanced");
> +		tc->link.base.caps.enhanced_framing ? "enhanced" : "default");
>  	dev_dbg(tc->dev, "Downspread: %s, scrambler: %s\n",
>  		tc->link.spread ? "0.5%" : "0.0%",
>  		tc->link.scrambler_dis ? "disabled" : "enabled");


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Re: [PATCH 14/21] drm/dp: Use drm_dp_aux_rd_interval()

[Philipp Zabel]

On Mon, 2019-08-05 at 14:23 +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Make use of the newly added drm_dp_aux_rd_interval() helper in existing
> DP link training helpers and add comments about minimum required delays
> mandated by the DP specification.

This patch does not add any comments:

> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/gpu/drm/drm_dp_helper.c | 26 +++-----------------------
>  1 file changed, 3 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 344f887fef2c..1fb3c27cd012 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -122,17 +122,7 @@ EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
>  
>  void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
>  {
> -	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> -					DP_TRAINING_AUX_RD_MASK;
> -
> -	if (rd_interval > 4)
> -		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
> -			      rd_interval);
> -
> -	if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
> -		rd_interval = 100;
> -	else
> -		rd_interval *= 4;
> +	unsigned int rd_interval = drm_dp_aux_rd_interval(dpcd);
>  
>  	usleep_range(rd_interval, rd_interval * 2);
>  }
> @@ -140,19 +130,9 @@ EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
>  
>  void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
>  {
> -	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> -					DP_TRAINING_AUX_RD_MASK;
> -
> -	if (rd_interval > 4)
> -		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
> -			      rd_interval);
> +	unsigned int min = drm_dp_aux_rd_interval(dpcd);
>  
> -	if (rd_interval == 0)
> -		rd_interval = 400;
> -	else
> -		rd_interval *= 4;
> -
> -	usleep_range(rd_interval, rd_interval * 2);
> +	usleep_range(min, min * 2);
>  }
>  EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
>  

regards
Philipp
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Re: [PATCH 20/21] drm/dp: Fix a couple of whitespace issues

[Philipp Zabel]

On Mon, 2019-08-05 at 14:23 +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Remove a gratuituous blank line in one place and add a blank line in
> another to improve readability.

Seems like the comment description is outdated here as well.

> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/gpu/drm/drm_dp_helper.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 136ee609f2ee..6b4431bade3e 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -216,7 +216,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
>  		}
>  
>  		ret = aux->transfer(aux, &msg);
> -
>  		if (ret >= 0) {
>  			native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK;
>  			if (native_reply == DP_AUX_NATIVE_REPLY_ACK) {

regards
Philipp
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Re: [PATCH 06/21] drm/dp: Probe link using existing parsing helpers

[Philipp Zabel]

On Mon, 2019-08-05 at 14:23 +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Use existing parsing helpers to probe a DisplayPort link.
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp
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Re: [PATCH 07/21] drm/dp: Read fast training capability from link

[Philipp Zabel]

On Mon, 2019-08-05 at 14:23 +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> While probing the DisplayPort link, query the fast training capability.
> If supported, drivers can use the fast link training sequence instead of
> the more involved full link training sequence.
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp
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Re: [PATCH 13/21] drm/dp: Do not busy-loop during link training

[Philipp Zabel]

On Mon, 2019-08-05 at 14:23 +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Use microsecond sleeps for the clock recovery and channel equalization
> delays during link training. The duration of these delays can be from
> 100 us up to 16 ms. It is rude to busy-loop for that amount of time.
> 
> While at it, also convert to standard coding style by putting the
> opening braces in a function definition on a new line.
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/gpu/drm/drm_dp_helper.c | 30 ++++++++++++++++++------------
>  1 file changed, 18 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 4112570dbe67..344f887fef2c 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -120,33 +120,39 @@ u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SI
>  }
>  EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
>  
> -void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) {
> -	int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> -			  DP_TRAINING_AUX_RD_MASK;
> +void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> +{
> +	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> +					DP_TRAINING_AUX_RD_MASK;
>  
>  	if (rd_interval > 4)
> -		DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n",
> +		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
>  			      rd_interval);
>  
>  	if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
> -		udelay(100);
> +		rd_interval = 100;
>  	else
> -		mdelay(rd_interval * 4);

rd_interval was in units of 4 ms.

> +		rd_interval *= 4;

This should be *= 4000 since the result is fed into usleep_range instead
of mdelay.

> +
> +	usleep_range(rd_interval, rd_interval * 2);
>  }
>  EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
>  
> -void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) {
> -	int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> -			  DP_TRAINING_AUX_RD_MASK;
> +void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> +{
> +	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> +					DP_TRAINING_AUX_RD_MASK;
>  
>  	if (rd_interval > 4)
> -		DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n",
> +		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
>  			      rd_interval);
>  
>  	if (rd_interval == 0)
> -		udelay(400);
> +		rd_interval = 400;
>  	else
> -		mdelay(rd_interval * 4);
> +		rd_interval *= 4;

Same as above.

> +
> +	usleep_range(rd_interval, rd_interval * 2);
>  }
>  EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
>  

regards
Philipp
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Re: [PATCH 15/21] drm/dp: Add helper to get post-cursor adjustments

[Philipp Zabel]

On Mon, 2019-08-05 at 14:23 +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> If the transmitter supports pre-emphasis post cursor2 the sink will
> request adjustments in a similar way to how it requests adjustments to
> the voltage swing and pre-emphasis settings.
> 
> Add a helper to extract these adjustments on a per-lane basis from the
> DPCD link status.
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp
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Re: [PATCH 13/21] drm/dp: Do not busy-loop during link training

[Thierry Reding]

[-- Attachment #1.1: Type: text/plain, Size: 3013 bytes --]

On Thu, Aug 08, 2019 at 03:33:27PM +0200, Philipp Zabel wrote:
> On Mon, 2019-08-05 at 14:23 +0200, Thierry Reding wrote:
> > From: Thierry Reding <treding@nvidia.com>
> > 
> > Use microsecond sleeps for the clock recovery and channel equalization
> > delays during link training. The duration of these delays can be from
> > 100 us up to 16 ms. It is rude to busy-loop for that amount of time.
> > 
> > While at it, also convert to standard coding style by putting the
> > opening braces in a function definition on a new line.
> > 
> > Signed-off-by: Thierry Reding <treding@nvidia.com>
> > ---
> >  drivers/gpu/drm/drm_dp_helper.c | 30 ++++++++++++++++++------------
> >  1 file changed, 18 insertions(+), 12 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> > index 4112570dbe67..344f887fef2c 100644
> > --- a/drivers/gpu/drm/drm_dp_helper.c
> > +++ b/drivers/gpu/drm/drm_dp_helper.c
> > @@ -120,33 +120,39 @@ u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SI
> >  }
> >  EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
> >  
> > -void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) {
> > -	int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> > -			  DP_TRAINING_AUX_RD_MASK;
> > +void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> > +{
> > +	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> > +					DP_TRAINING_AUX_RD_MASK;
> >  
> >  	if (rd_interval > 4)
> > -		DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n",
> > +		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
> >  			      rd_interval);
> >  
> >  	if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
> > -		udelay(100);
> > +		rd_interval = 100;
> >  	else
> > -		mdelay(rd_interval * 4);
> 
> rd_interval was in units of 4 ms.
> 
> > +		rd_interval *= 4;
> 
> This should be *= 4000 since the result is fed into usleep_range instead
> of mdelay.

Good catch! Fixed in v2.

> 
> > +
> > +	usleep_range(rd_interval, rd_interval * 2);
> >  }
> >  EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
> >  
> > -void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) {
> > -	int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> > -			  DP_TRAINING_AUX_RD_MASK;
> > +void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> > +{
> > +	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> > +					DP_TRAINING_AUX_RD_MASK;
> >  
> >  	if (rd_interval > 4)
> > -		DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n",
> > +		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
> >  			      rd_interval);
> >  
> >  	if (rd_interval == 0)
> > -		udelay(400);
> > +		rd_interval = 400;
> >  	else
> > -		mdelay(rd_interval * 4);
> > +		rd_interval *= 4;
> 
> Same as above.

Fixed in v2.

Thanks,
Thierry

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Re: [PATCH 14/21] drm/dp: Use drm_dp_aux_rd_interval()

[Thierry Reding]

[-- Attachment #1.1: Type: text/plain, Size: 2481 bytes --]

On Thu, Aug 08, 2019 at 03:17:33PM +0200, Philipp Zabel wrote:
> On Mon, 2019-08-05 at 14:23 +0200, Thierry Reding wrote:
> > From: Thierry Reding <treding@nvidia.com>
> > 
> > Make use of the newly added drm_dp_aux_rd_interval() helper in existing
> > DP link training helpers and add comments about minimum required delays
> > mandated by the DP specification.
> 
> This patch does not add any comments:

Indeed, I think this is a left-over comment from when this hadn't been
split apart from patch "drm/dp: Read AUX read interval from DPCD".

I've dropped that second part in v2.

Thierry

> 
> > 
> > Signed-off-by: Thierry Reding <treding@nvidia.com>
> > ---
> >  drivers/gpu/drm/drm_dp_helper.c | 26 +++-----------------------
> >  1 file changed, 3 insertions(+), 23 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> > index 344f887fef2c..1fb3c27cd012 100644
> > --- a/drivers/gpu/drm/drm_dp_helper.c
> > +++ b/drivers/gpu/drm/drm_dp_helper.c
> > @@ -122,17 +122,7 @@ EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
> >  
> >  void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> >  {
> > -	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> > -					DP_TRAINING_AUX_RD_MASK;
> > -
> > -	if (rd_interval > 4)
> > -		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
> > -			      rd_interval);
> > -
> > -	if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
> > -		rd_interval = 100;
> > -	else
> > -		rd_interval *= 4;
> > +	unsigned int rd_interval = drm_dp_aux_rd_interval(dpcd);
> >  
> >  	usleep_range(rd_interval, rd_interval * 2);
> >  }
> > @@ -140,19 +130,9 @@ EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
> >  
> >  void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
> >  {
> > -	unsigned int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
> > -					DP_TRAINING_AUX_RD_MASK;
> > -
> > -	if (rd_interval > 4)
> > -		DRM_DEBUG_KMS("AUX interval %u, out of range (max 4)\n",
> > -			      rd_interval);
> > +	unsigned int min = drm_dp_aux_rd_interval(dpcd);
> >  
> > -	if (rd_interval == 0)
> > -		rd_interval = 400;
> > -	else
> > -		rd_interval *= 4;
> > -
> > -	usleep_range(rd_interval, rd_interval * 2);
> > +	usleep_range(min, min * 2);
> >  }
> >  EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
> >  
> 
> regards
> Philipp

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Re: [PATCH 20/21] drm/dp: Fix a couple of whitespace issues

[Thierry Reding]

[-- Attachment #1.1: Type: text/plain, Size: 1411 bytes --]

On Thu, Aug 08, 2019 at 03:18:47PM +0200, Philipp Zabel wrote:
> On Mon, 2019-08-05 at 14:23 +0200, Thierry Reding wrote:
> > From: Thierry Reding <treding@nvidia.com>
> > 
> > Remove a gratuituous blank line in one place and add a blank line in
> > another to improve readability.
> 
> Seems like the comment description is outdated here as well.

Indeed. I've had these patches in a development branch for a very long
time because the hardware that I used to test DP support on stopped
working and I only recently revived this on a different platform that
also has a DP output. Looks like that other blank line had been added by
some other commit in the meantime.

Fixed in v2.

Thanks,
Thierry

> 
> > Signed-off-by: Thierry Reding <treding@nvidia.com>
> > ---
> >  drivers/gpu/drm/drm_dp_helper.c | 1 -
> >  1 file changed, 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> > index 136ee609f2ee..6b4431bade3e 100644
> > --- a/drivers/gpu/drm/drm_dp_helper.c
> > +++ b/drivers/gpu/drm/drm_dp_helper.c
> > @@ -216,7 +216,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
> >  		}
> >  
> >  		ret = aux->transfer(aux, &msg);
> > -
> >  		if (ret >= 0) {
> >  			native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK;
> >  			if (native_reply == DP_AUX_NATIVE_REPLY_ACK) {
> 
> regards
> Philipp

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