[PATCH 1/2] drm: bridge: dw-mipi-dsi: Handle NO_EOT_PACKET mode

[PATCH 1/2] drm: bridge: dw-mipi-dsi: Handle NO_EOT_PACKET mode

[Jagan Teki]

Many downstream bridges or panels followed by dw-mipi-dsi were
using MIPI_DSI_MODE_NO_EOT_PACKET.

So, handle the EOTP bits accordingly in the dw-mipi-dsi host.

Signed-off-by: Jagan Teki <jagan@edgeble.ai>
---
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index b2efecf7d160..47bd69d5ac99 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -664,7 +664,13 @@ static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
 
 static void dw_mipi_dsi_packet_handler_config(struct dw_mipi_dsi *dsi)
 {
-	dsi_write(dsi, DSI_PCKHDL_CFG, CRC_RX_EN | ECC_RX_EN | BTA_EN);
+	u32 val;
+
+	val = CRC_RX_EN | ECC_RX_EN | BTA_EN | EOTP_TX_EN;
+	if (dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)
+		val &= ~EOTP_TX_EN;
+
+	dsi_write(dsi, DSI_PCKHDL_CFG, val);
 }
 
 static void dw_mipi_dsi_video_packet_config(struct dw_mipi_dsi *dsi,
-- 
2.25.1

[PATCH 2/2] drm: bridge: dw-mipi-dsi: Switch to regmap support

[Jagan Teki]

To make debugging easier, switch the driver to use regmap
from conventional io calls.

Signed-off-by: Jagan Teki <jagan@edgeble.ai>
---
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 81 ++++++++++++-------
 1 file changed, 54 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index 47bd69d5ac99..62a160af4047 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/regmap.h>
 #include <linux/reset.h>
 
 #include <video/mipi_display.h>
@@ -242,7 +243,7 @@ struct dw_mipi_dsi {
 	struct mipi_dsi_host dsi_host;
 	struct drm_bridge *panel_bridge;
 	struct device *dev;
-	void __iomem *base;
+	struct regmap *regmap;
 
 	struct clk *pclk;
 
@@ -301,12 +302,16 @@ static inline struct dw_mipi_dsi *bridge_to_dsi(struct drm_bridge *bridge)
 
 static inline void dsi_write(struct dw_mipi_dsi *dsi, u32 reg, u32 val)
 {
-	writel(val, dsi->base + reg);
+	regmap_write(dsi->regmap, reg, val);
 }
 
 static inline u32 dsi_read(struct dw_mipi_dsi *dsi, u32 reg)
 {
-	return readl(dsi->base + reg);
+	u32 val;
+
+	regmap_read(dsi->regmap, reg, &val);
+
+	return val;
 }
 
 static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
@@ -332,6 +337,7 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
 	if (IS_ERR(bridge))
 		return PTR_ERR(bridge);
 
+	dev_info(host->dev, "Attached device %s\n", device->name);
 	dsi->panel_bridge = bridge;
 
 	drm_bridge_add(&dsi->bridge);
@@ -400,9 +406,9 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
 	int ret;
 	u32 val, mask;
 
-	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
-				 val, !(val & GEN_CMD_FULL), 1000,
-				 CMD_PKT_STATUS_TIMEOUT_US);
+	ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
+				       val, !(val & GEN_CMD_FULL), 1000,
+				       CMD_PKT_STATUS_TIMEOUT_US);
 	if (ret) {
 		dev_err(dsi->dev, "failed to get available command FIFO\n");
 		return ret;
@@ -411,9 +417,9 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
 	dsi_write(dsi, DSI_GEN_HDR, hdr_val);
 
 	mask = GEN_CMD_EMPTY | GEN_PLD_W_EMPTY;
-	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
-				 val, (val & mask) == mask,
-				 1000, CMD_PKT_STATUS_TIMEOUT_US);
+	ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
+				       val, (val & mask) == mask,
+				       1000, CMD_PKT_STATUS_TIMEOUT_US);
 	if (ret) {
 		dev_err(dsi->dev, "failed to write command FIFO\n");
 		return ret;
@@ -443,9 +449,9 @@ static int dw_mipi_dsi_write(struct dw_mipi_dsi *dsi,
 			len -= pld_data_bytes;
 		}
 
-		ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
-					 val, !(val & GEN_PLD_W_FULL), 1000,
-					 CMD_PKT_STATUS_TIMEOUT_US);
+		ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
+					       val, !(val & GEN_PLD_W_FULL), 1000,
+					       CMD_PKT_STATUS_TIMEOUT_US);
 		if (ret) {
 			dev_err(dsi->dev,
 				"failed to get available write payload FIFO\n");
@@ -466,9 +472,9 @@ static int dw_mipi_dsi_read(struct dw_mipi_dsi *dsi,
 	u32 val;
 
 	/* Wait end of the read operation */
-	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
-				 val, !(val & GEN_RD_CMD_BUSY),
-				 1000, CMD_PKT_STATUS_TIMEOUT_US);
+	ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
+				       val, !(val & GEN_RD_CMD_BUSY), 1000,
+				       CMD_PKT_STATUS_TIMEOUT_US);
 	if (ret) {
 		dev_err(dsi->dev, "Timeout during read operation\n");
 		return ret;
@@ -476,9 +482,9 @@ static int dw_mipi_dsi_read(struct dw_mipi_dsi *dsi,
 
 	for (i = 0; i < len; i += 4) {
 		/* Read fifo must not be empty before all bytes are read */
-		ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
-					 val, !(val & GEN_PLD_R_EMPTY),
-					 1000, CMD_PKT_STATUS_TIMEOUT_US);
+		ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
+					       val, !(val & GEN_PLD_R_EMPTY), 1000,
+					       CMD_PKT_STATUS_TIMEOUT_US);
 		if (ret) {
 			dev_err(dsi->dev, "Read payload FIFO is empty\n");
 			return ret;
@@ -499,6 +505,9 @@ static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host,
 	struct mipi_dsi_packet packet;
 	int ret, nb_bytes;
 
+	DRM_INFO("%x %x %x\n", msg->type,
+		 ((((u8 *)msg->tx_buf)[0] << 8) >> 8),
+		 ((((u8 *)msg->tx_buf)[1] << 16)) >> 16);
 	ret = mipi_dsi_create_packet(&packet, msg);
 	if (ret) {
 		dev_err(dsi->dev, "failed to create packet: %d\n", ret);
@@ -828,17 +837,18 @@ static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi)
 	u32 val;
 	int ret;
 
-	dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENFORCEPLL | PHY_ENABLECLK |
+	dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENABLECLK |
 		  PHY_UNRSTZ | PHY_UNSHUTDOWNZ);
 
-	ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS, val,
-				 val & PHY_LOCK, 1000, PHY_STATUS_TIMEOUT_US);
+	ret = regmap_read_poll_timeout(dsi->regmap, DSI_PHY_STATUS,
+				       val, val & PHY_LOCK, 1000,
+				       PHY_STATUS_TIMEOUT_US);
 	if (ret)
 		DRM_DEBUG_DRIVER("failed to wait phy lock state\n");
 
-	ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS,
-				 val, val & PHY_STOP_STATE_CLK_LANE, 1000,
-				 PHY_STATUS_TIMEOUT_US);
+	ret = regmap_read_poll_timeout(dsi->regmap, DSI_PHY_STATUS,
+				       val, val & PHY_STOP_STATE_CLK_LANE, 1000,
+				       PHY_STATUS_TIMEOUT_US);
 	if (ret)
 		DRM_DEBUG_DRIVER("failed to wait phy clk lane stop state\n");
 }
@@ -1103,6 +1113,14 @@ static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi) { }
 
 #endif /* CONFIG_DEBUG_FS */
 
+static const struct regmap_config dw_mipi_dsi_regmap_config = {
+	.name = "dw-mipi-dsi",
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = DSI_INT_MSK1,
+};
+
 static struct dw_mipi_dsi *
 __dw_mipi_dsi_probe(struct platform_device *pdev,
 		    const struct dw_mipi_dsi_plat_data *plat_data)
@@ -1110,6 +1128,7 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
 	struct device *dev = &pdev->dev;
 	struct reset_control *apb_rst;
 	struct dw_mipi_dsi *dsi;
+	void __iomem *base;
 	int ret;
 
 	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
@@ -1126,12 +1145,20 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
 	}
 
 	if (!plat_data->base) {
-		dsi->base = devm_platform_ioremap_resource(pdev, 0);
-		if (IS_ERR(dsi->base))
+		base = devm_platform_ioremap_resource(pdev, 0);
+		if (IS_ERR(base))
 			return ERR_PTR(-ENODEV);
 
 	} else {
-		dsi->base = plat_data->base;
+		base = plat_data->base;
+	}
+
+	dsi->regmap = devm_regmap_init_mmio(dev, base,
+					    &dw_mipi_dsi_regmap_config);
+	if (IS_ERR(dsi->regmap)) {
+		ret = PTR_ERR(dsi->regmap);
+		dev_err(dev, "failed to init register map\n");
+		return ERR_PTR(ret);
 	}
 
 	dsi->pclk = devm_clk_get(dev, "pclk");
-- 
2.25.1

Re: [PATCH 2/2] drm: bridge: dw-mipi-dsi: Switch to regmap support

[Sam Ravnborg]

Hi Jagan

The change to regmap looks nice. But two small comments below,
just some drive-by comments.

	Sam

On Tue, Jan 24, 2023 at 12:16:47AM +0530, Jagan Teki wrote:
> To make debugging easier, switch the driver to use regmap
> from conventional io calls.
> 
> Signed-off-by: Jagan Teki <jagan@edgeble.ai>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 81 ++++++++++++-------
>  1 file changed, 54 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index 47bd69d5ac99..62a160af4047 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -15,6 +15,7 @@
>  #include <linux/module.h>
>  #include <linux/of_device.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
>  #include <linux/reset.h>
>  
>  #include <video/mipi_display.h>
> @@ -242,7 +243,7 @@ struct dw_mipi_dsi {
>  	struct mipi_dsi_host dsi_host;
>  	struct drm_bridge *panel_bridge;
>  	struct device *dev;
> -	void __iomem *base;
> +	struct regmap *regmap;
>  
>  	struct clk *pclk;
>  
> @@ -301,12 +302,16 @@ static inline struct dw_mipi_dsi *bridge_to_dsi(struct drm_bridge *bridge)
>  
>  static inline void dsi_write(struct dw_mipi_dsi *dsi, u32 reg, u32 val)
>  {
> -	writel(val, dsi->base + reg);
> +	regmap_write(dsi->regmap, reg, val);
>  }
>  
>  static inline u32 dsi_read(struct dw_mipi_dsi *dsi, u32 reg)
>  {
> -	return readl(dsi->base + reg);
> +	u32 val;
> +
> +	regmap_read(dsi->regmap, reg, &val);
> +
> +	return val;
>  }
>  
>  static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
> @@ -332,6 +337,7 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
>  	if (IS_ERR(bridge))
>  		return PTR_ERR(bridge);
>  
> +	dev_info(host->dev, "Attached device %s\n", device->name);
>  	dsi->panel_bridge = bridge;
>  
>  	drm_bridge_add(&dsi->bridge);
> @@ -400,9 +406,9 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
>  	int ret;
>  	u32 val, mask;
>  
> -	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
> -				 val, !(val & GEN_CMD_FULL), 1000,
> -				 CMD_PKT_STATUS_TIMEOUT_US);
> +	ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
> +				       val, !(val & GEN_CMD_FULL), 1000,
> +				       CMD_PKT_STATUS_TIMEOUT_US);
>  	if (ret) {
>  		dev_err(dsi->dev, "failed to get available command FIFO\n");
>  		return ret;
> @@ -411,9 +417,9 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
>  	dsi_write(dsi, DSI_GEN_HDR, hdr_val);
>  
>  	mask = GEN_CMD_EMPTY | GEN_PLD_W_EMPTY;
> -	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
> -				 val, (val & mask) == mask,
> -				 1000, CMD_PKT_STATUS_TIMEOUT_US);
> +	ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
> +				       val, (val & mask) == mask,
> +				       1000, CMD_PKT_STATUS_TIMEOUT_US);
>  	if (ret) {
>  		dev_err(dsi->dev, "failed to write command FIFO\n");
>  		return ret;
> @@ -443,9 +449,9 @@ static int dw_mipi_dsi_write(struct dw_mipi_dsi *dsi,
>  			len -= pld_data_bytes;
>  		}
>  
> -		ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
> -					 val, !(val & GEN_PLD_W_FULL), 1000,
> -					 CMD_PKT_STATUS_TIMEOUT_US);
> +		ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
> +					       val, !(val & GEN_PLD_W_FULL), 1000,
> +					       CMD_PKT_STATUS_TIMEOUT_US);
>  		if (ret) {
>  			dev_err(dsi->dev,
>  				"failed to get available write payload FIFO\n");
> @@ -466,9 +472,9 @@ static int dw_mipi_dsi_read(struct dw_mipi_dsi *dsi,
>  	u32 val;
>  
>  	/* Wait end of the read operation */
> -	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
> -				 val, !(val & GEN_RD_CMD_BUSY),
> -				 1000, CMD_PKT_STATUS_TIMEOUT_US);
> +	ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
> +				       val, !(val & GEN_RD_CMD_BUSY), 1000,
> +				       CMD_PKT_STATUS_TIMEOUT_US);
>  	if (ret) {
>  		dev_err(dsi->dev, "Timeout during read operation\n");
>  		return ret;
> @@ -476,9 +482,9 @@ static int dw_mipi_dsi_read(struct dw_mipi_dsi *dsi,
>  
>  	for (i = 0; i < len; i += 4) {
>  		/* Read fifo must not be empty before all bytes are read */
> -		ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
> -					 val, !(val & GEN_PLD_R_EMPTY),
> -					 1000, CMD_PKT_STATUS_TIMEOUT_US);
> +		ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
> +					       val, !(val & GEN_PLD_R_EMPTY), 1000,
> +					       CMD_PKT_STATUS_TIMEOUT_US);
>  		if (ret) {
>  			dev_err(dsi->dev, "Read payload FIFO is empty\n");
>  			return ret;
> @@ -499,6 +505,9 @@ static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host,
>  	struct mipi_dsi_packet packet;
>  	int ret, nb_bytes;
>  
> +	DRM_INFO("%x %x %x\n", msg->type,
> +		 ((((u8 *)msg->tx_buf)[0] << 8) >> 8),
> +		 ((((u8 *)msg->tx_buf)[1] << 16)) >> 16);
This looks like some debug left-over. If not, then please consider to
use drm_info or dev_info.
>  	ret = mipi_dsi_create_packet(&packet, msg);
>  	if (ret) {
>  		dev_err(dsi->dev, "failed to create packet: %d\n", ret);
> @@ -828,17 +837,18 @@ static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi)
>  	u32 val;
>  	int ret;
>  
> -	dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENFORCEPLL | PHY_ENABLECLK |
> +	dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENABLECLK |
>  		  PHY_UNRSTZ | PHY_UNSHUTDOWNZ);
This change is not related to the regmap conversion and should be
separated out.

	Sam

Re: [PATCH 1/2] drm: bridge: dw-mipi-dsi: Handle NO_EOT_PACKET mode

[Sam Ravnborg]

Hi Jagan.

One small drive-by comment.

On Tue, Jan 24, 2023 at 12:16:46AM +0530, Jagan Teki wrote:
> Many downstream bridges or panels followed by dw-mipi-dsi were
> using MIPI_DSI_MODE_NO_EOT_PACKET.
> 
> So, handle the EOTP bits accordingly in the dw-mipi-dsi host.
> 
> Signed-off-by: Jagan Teki <jagan@edgeble.ai>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index b2efecf7d160..47bd69d5ac99 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -664,7 +664,13 @@ static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
>  
>  static void dw_mipi_dsi_packet_handler_config(struct dw_mipi_dsi *dsi)
>  {
> -	dsi_write(dsi, DSI_PCKHDL_CFG, CRC_RX_EN | ECC_RX_EN | BTA_EN);
> +	u32 val;
> +
> +	val = CRC_RX_EN | ECC_RX_EN | BTA_EN | EOTP_TX_EN;
> +	if (dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)
> +		val &= ~EOTP_TX_EN;

I had to look twice because the bit is set, and then maybe cleared.

	val = CRC_RX_EN | ECC_RX_EN | BTA_EN | EOTP_TX_EN;
	if (!(dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET))
		val |= EOTP_TX_EN;
?

	Sam

Re: [PATCH 1/2] drm: bridge: dw-mipi-dsi: Handle NO_EOT_PACKET mode

[Jagan Teki]

On Tue, 24 Jan 2023 at 01:49, Sam Ravnborg <sam@ravnborg.org> wrote:
>
> Hi Jagan.
>
> One small drive-by comment.
>
> On Tue, Jan 24, 2023 at 12:16:46AM +0530, Jagan Teki wrote:
> > Many downstream bridges or panels followed by dw-mipi-dsi were
> > using MIPI_DSI_MODE_NO_EOT_PACKET.
> >
> > So, handle the EOTP bits accordingly in the dw-mipi-dsi host.
> >
> > Signed-off-by: Jagan Teki <jagan@edgeble.ai>
> > ---
> >  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> > index b2efecf7d160..47bd69d5ac99 100644
> > --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> > +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> > @@ -664,7 +664,13 @@ static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
> >
> >  static void dw_mipi_dsi_packet_handler_config(struct dw_mipi_dsi *dsi)
> >  {
> > -     dsi_write(dsi, DSI_PCKHDL_CFG, CRC_RX_EN | ECC_RX_EN | BTA_EN);
> > +     u32 val;
> > +
> > +     val = CRC_RX_EN | ECC_RX_EN | BTA_EN | EOTP_TX_EN;
> > +     if (dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)
> > +             val &= ~EOTP_TX_EN;
>
> I had to look twice because the bit is set, and then maybe cleared.
>
>         val = CRC_RX_EN | ECC_RX_EN | BTA_EN | EOTP_TX_EN;
>         if (!(dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET))
>                 val |= EOTP_TX_EN;
> ?

What I understand is if NO_EOT means we need to disable EOTP_TX_EN bit
so the logic in the patch does the same. Enable the EOTP_TX_EN by
default and disable it if NO_EOT mode set.

Jagan.