[v10.1,14/17] drm: bridge: analogix/dp: try force hpd after plug in lookup failed
diff mbox

Message ID 1449627039-15689-1-git-send-email-ykk@rock-chips.com
State New
Headers show

Commit Message

Yakir Yang Dec. 9, 2015, 2:10 a.m. UTC
Some edp screen do not have hpd signal, so we can't just return
failed when hpd plug in detect failed.

This is an hardware property, so we need add a devicetree property
"analogix,need-force-hpd" to indicate this sutiation.

Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
---
Changes in v10.1:
- Rename the "analogix,need-force-hpd" to common 'force-hpd' (Rob)

Changes in v9: None
Changes in v8: None
Changes in v7: None
Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3:
- Add "analogix,need-force-hpd" to indicate whether driver need foce
  hpd when hpd detect failed.

Changes in v2: None

 .../bindings/display/bridge/analogix_dp.txt        |  4 ++-
 .../bindings/display/exynos/exynos_dp.txt          |  1 +
 .../display/rockchip/analogix_dp-rockchip.txt      |  1 +
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 35 ++++++++++++++++++----
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.h |  2 ++
 drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c  |  9 ++++++
 6 files changed, 46 insertions(+), 6 deletions(-)

Comments

Rob Herring Dec. 9, 2015, 4:25 a.m. UTC | #1
On Wed, Dec 09, 2015 at 10:10:39AM +0800, Yakir Yang wrote:
> Some edp screen do not have hpd signal, so we can't just return
> failed when hpd plug in detect failed.
> 
> This is an hardware property, so we need add a devicetree property
> "analogix,need-force-hpd" to indicate this sutiation.
> 
> Signed-off-by: Yakir Yang <ykk@rock-chips.com>
> Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>

Acked-by: Rob Herring <robh@kernel.org>

> ---
> Changes in v10.1:
> - Rename the "analogix,need-force-hpd" to common 'force-hpd' (Rob)
> 
> Changes in v9: None
> Changes in v8: None
> Changes in v7: None
> Changes in v6: None
> Changes in v5: None
> Changes in v4: None
> Changes in v3:
> - Add "analogix,need-force-hpd" to indicate whether driver need foce
>   hpd when hpd detect failed.
> 
> Changes in v2: None
> 
>  .../bindings/display/bridge/analogix_dp.txt        |  4 ++-
>  .../bindings/display/exynos/exynos_dp.txt          |  1 +
>  .../display/rockchip/analogix_dp-rockchip.txt      |  1 +
>  drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 35 ++++++++++++++++++----
>  drivers/gpu/drm/bridge/analogix/analogix_dp_core.h |  2 ++
>  drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c  |  9 ++++++
>  6 files changed, 46 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt b/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
> index 7659a7a..4f2ba8c 100644
> --- a/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
> +++ b/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
> @@ -22,6 +22,9 @@ Required properties for dp-controller:
>  		from general PHY binding: Should be "dp".
>  
>  Optional properties for dp-controller:
> +	-force-hpd:
> +		Indicate driver need force hpd when hpd detect failed, this
> +		is used for some eDP screen which don't have hpd signal.
>  	-hpd-gpios:
>  		Hotplug detect GPIO.
>  		Indicates which GPIO should be used for hotplug detection
> @@ -31,7 +34,6 @@ Optional properties for dp-controller:
>  		* Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
>  		* Documentation/devicetree/bindings/video/analogix_dp-rockchip.txt
>  
> -
>  [1]: Documentation/devicetree/bindings/media/video-interfaces.txt
>  -------------------------------------------------------------------------------
>  
> diff --git a/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt b/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
> index 9905081..8800164 100644
> --- a/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
> +++ b/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
> @@ -41,6 +41,7 @@ For the below properties, please refer to Analogix DP binding document:
>  	-phys (required)
>  	-phy-names (required)
>  	-hpd-gpios (optional)
> +	-analogix,need-force-hpd (optional)
>  	-video interfaces (optional)
>  
>  Deprecated properties for DisplayPort:
> diff --git a/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt b/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
> index dae86c4..187a708e 100644
> --- a/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
> +++ b/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
> @@ -32,6 +32,7 @@ For the below properties, please refer to Analogix DP binding document:
>  - phys (required)
>  - phy-names (required)
>  - hpd-gpios (optional)
> +- force-hpd (optional)
>  -------------------------------------------------------------------------------
>  
>  Example:
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index a11504b..00aee44 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -59,15 +59,38 @@ static int analogix_dp_detect_hpd(struct analogix_dp_device *dp)
>  {
>  	int timeout_loop = 0;
>  
> -	while (analogix_dp_get_plug_in_status(dp) != 0) {
> +	while (timeout_loop < DP_TIMEOUT_LOOP_COUNT) {
> +		if (analogix_dp_get_plug_in_status(dp) == 0)
> +			return 0;
> +
>  		timeout_loop++;
> -		if (timeout_loop > DP_TIMEOUT_LOOP_COUNT) {
> -			dev_err(dp->dev, "failed to get hpd plug status\n");
> -			return -ETIMEDOUT;
> -		}
>  		usleep_range(10, 11);
>  	}
>  
> +	/*
> +	 * Some edp screen do not have hpd signal, so we can't just
> +	 * return failed when hpd plug in detect failed, DT property
> +	 * "need-force-hpd" would indicate whether driver need this.
> +	 */
> +	if (!dp->force_hpd)
> +		return -ETIMEDOUT;
> +
> +	/*
> +	 * The eDP TRM indicate that if HPD_STATUS(RO) is 0, AUX CH
> +	 * will not work, so we need to give a force hpd action to
> +	 * set HPD_STATUS manually.
> +	 */
> +	dev_dbg(dp->dev, "failed to get hpd plug status, try to force hpd\n");
> +
> +	analogix_dp_force_hpd(dp);
> +
> +	if (analogix_dp_get_plug_in_status(dp) != 0) {
> +		dev_err(dp->dev, "failed to get hpd plug in status\n");
> +		return -EINVAL;
> +	}
> +
> +	dev_dbg(dp->dev, "success to get plug in status after force hpd\n");
> +
>  	return 0;
>  }
>  
> @@ -1246,6 +1269,8 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
>  	if (IS_ERR(dp->reg_base))
>  		return PTR_ERR(dp->reg_base);
>  
> +	dp->force_hpd = of_property_read_bool(dev->of_node, "force-hpd");
> +
>  	dp->hpd_gpio = of_get_named_gpio(dev->of_node, "hpd-gpios", 0);
>  	if (!gpio_is_valid(dp->hpd_gpio))
>  		dp->hpd_gpio = of_get_named_gpio(dev->of_node,
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
> index e6f8243..07e147c 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
> @@ -160,6 +160,7 @@ struct analogix_dp_device {
>  	struct phy		*phy;
>  	int			dpms_mode;
>  	int			hpd_gpio;
> +	bool                    force_hpd;
>  
>  	struct analogix_dp_plat_data *plat_data;
>  };
> @@ -180,6 +181,7 @@ void analogix_dp_set_analog_power_down(struct analogix_dp_device *dp,
>  				       bool enable);
>  void analogix_dp_init_analog_func(struct analogix_dp_device *dp);
>  void analogix_dp_init_hpd(struct analogix_dp_device *dp);
> +void analogix_dp_force_hpd(struct analogix_dp_device *dp);
>  enum dp_irq_type analogix_dp_get_irq_type(struct analogix_dp_device *dp);
>  void analogix_dp_clear_hotplug_interrupts(struct analogix_dp_device *dp);
>  void analogix_dp_reset_aux(struct analogix_dp_device *dp);
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> index 21a3287..c7e2959 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> @@ -365,6 +365,15 @@ void analogix_dp_init_hpd(struct analogix_dp_device *dp)
>  	writel(reg, dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
>  }
>  
> +void analogix_dp_force_hpd(struct analogix_dp_device *dp)
> +{
> +	u32 reg;
> +
> +	reg = readl(dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
> +	reg = (F_HPD | HPD_CTRL);
> +	writel(reg, dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
> +}
> +
>  enum dp_irq_type analogix_dp_get_irq_type(struct analogix_dp_device *dp)
>  {
>  	u32 reg;
> -- 
> 1.9.1
> 
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
Yakir Yang Dec. 9, 2015, 5:55 a.m. UTC | #2
Hi Rob,

On 12/09/2015 12:25 PM, Rob Herring wrote:
> On Wed, Dec 09, 2015 at 10:10:39AM +0800, Yakir Yang wrote:
>> Some edp screen do not have hpd signal, so we can't just return
>> failed when hpd plug in detect failed.
>>
>> This is an hardware property, so we need add a devicetree property
>> "analogix,need-force-hpd" to indicate this sutiation.
>>
>> Signed-off-by: Yakir Yang <ykk@rock-chips.com>
>> Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
> Acked-by: Rob Herring <robh@kernel.org>

Thanks,

>
>> ---
>> Changes in v10.1:
>> - Rename the "analogix,need-force-hpd" to common 'force-hpd' (Rob)
>>
>> Changes in v9: None
>> Changes in v8: None
>> Changes in v7: None
>> Changes in v6: None
>> Changes in v5: None
>> Changes in v4: None
>> Changes in v3:
>> - Add "analogix,need-force-hpd" to indicate whether driver need foce
>>    hpd when hpd detect failed.
>>
>> Changes in v2: None
>>
>>   .../bindings/display/bridge/analogix_dp.txt        |  4 ++-
>>   .../bindings/display/exynos/exynos_dp.txt          |  1 +
>>   .../display/rockchip/analogix_dp-rockchip.txt      |  1 +
>>   drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 35 ++++++++++++++++++----
>>   drivers/gpu/drm/bridge/analogix/analogix_dp_core.h |  2 ++
>>   drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c  |  9 ++++++
>>   6 files changed, 46 insertions(+), 6 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt b/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
>> index 7659a7a..4f2ba8c 100644
>> --- a/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
>> +++ b/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
>> @@ -22,6 +22,9 @@ Required properties for dp-controller:
>>   		from general PHY binding: Should be "dp".
>>   
>>   Optional properties for dp-controller:
>> +	-force-hpd:
>> +		Indicate driver need force hpd when hpd detect failed, this
>> +		is used for some eDP screen which don't have hpd signal.
>>   	-hpd-gpios:
>>   		Hotplug detect GPIO.
>>   		Indicates which GPIO should be used for hotplug detection
>> @@ -31,7 +34,6 @@ Optional properties for dp-controller:
>>   		* Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
>>   		* Documentation/devicetree/bindings/video/analogix_dp-rockchip.txt
>>   
>> -
>>   [1]: Documentation/devicetree/bindings/media/video-interfaces.txt
>>   -------------------------------------------------------------------------------
>>   
>> diff --git a/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt b/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
>> index 9905081..8800164 100644
>> --- a/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
>> +++ b/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
>> @@ -41,6 +41,7 @@ For the below properties, please refer to Analogix DP binding document:
>>   	-phys (required)
>>   	-phy-names (required)
>>   	-hpd-gpios (optional)
>> +	-analogix,need-force-hpd (optional)

Forget about this one, will send the new version to fix this, and carry 
your ack.


- Yakir

>>   	-video interfaces (optional)
>>   
>>   Deprecated properties for DisplayPort:
>> diff --git a/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt b/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
>> index dae86c4..187a708e 100644
>> --- a/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
>> +++ b/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
>> @@ -32,6 +32,7 @@ For the below properties, please refer to Analogix DP binding document:
>>   - phys (required)
>>   - phy-names (required)
>>   - hpd-gpios (optional)
>> +- force-hpd (optional)
>>   -------------------------------------------------------------------------------
>>   
>>   Example:
>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> index a11504b..00aee44 100644
>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
>> @@ -59,15 +59,38 @@ static int analogix_dp_detect_hpd(struct analogix_dp_device *dp)
>>   {
>>   	int timeout_loop = 0;
>>   
>> -	while (analogix_dp_get_plug_in_status(dp) != 0) {
>> +	while (timeout_loop < DP_TIMEOUT_LOOP_COUNT) {
>> +		if (analogix_dp_get_plug_in_status(dp) == 0)
>> +			return 0;
>> +
>>   		timeout_loop++;
>> -		if (timeout_loop > DP_TIMEOUT_LOOP_COUNT) {
>> -			dev_err(dp->dev, "failed to get hpd plug status\n");
>> -			return -ETIMEDOUT;
>> -		}
>>   		usleep_range(10, 11);
>>   	}
>>   
>> +	/*
>> +	 * Some edp screen do not have hpd signal, so we can't just
>> +	 * return failed when hpd plug in detect failed, DT property
>> +	 * "need-force-hpd" would indicate whether driver need this.
>> +	 */
>> +	if (!dp->force_hpd)
>> +		return -ETIMEDOUT;
>> +
>> +	/*
>> +	 * The eDP TRM indicate that if HPD_STATUS(RO) is 0, AUX CH
>> +	 * will not work, so we need to give a force hpd action to
>> +	 * set HPD_STATUS manually.
>> +	 */
>> +	dev_dbg(dp->dev, "failed to get hpd plug status, try to force hpd\n");
>> +
>> +	analogix_dp_force_hpd(dp);
>> +
>> +	if (analogix_dp_get_plug_in_status(dp) != 0) {
>> +		dev_err(dp->dev, "failed to get hpd plug in status\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	dev_dbg(dp->dev, "success to get plug in status after force hpd\n");
>> +
>>   	return 0;
>>   }
>>   
>> @@ -1246,6 +1269,8 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
>>   	if (IS_ERR(dp->reg_base))
>>   		return PTR_ERR(dp->reg_base);
>>   
>> +	dp->force_hpd = of_property_read_bool(dev->of_node, "force-hpd");
>> +
>>   	dp->hpd_gpio = of_get_named_gpio(dev->of_node, "hpd-gpios", 0);
>>   	if (!gpio_is_valid(dp->hpd_gpio))
>>   		dp->hpd_gpio = of_get_named_gpio(dev->of_node,
>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
>> index e6f8243..07e147c 100644
>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
>> @@ -160,6 +160,7 @@ struct analogix_dp_device {
>>   	struct phy		*phy;
>>   	int			dpms_mode;
>>   	int			hpd_gpio;
>> +	bool                    force_hpd;
>>   
>>   	struct analogix_dp_plat_data *plat_data;
>>   };
>> @@ -180,6 +181,7 @@ void analogix_dp_set_analog_power_down(struct analogix_dp_device *dp,
>>   				       bool enable);
>>   void analogix_dp_init_analog_func(struct analogix_dp_device *dp);
>>   void analogix_dp_init_hpd(struct analogix_dp_device *dp);
>> +void analogix_dp_force_hpd(struct analogix_dp_device *dp);
>>   enum dp_irq_type analogix_dp_get_irq_type(struct analogix_dp_device *dp);
>>   void analogix_dp_clear_hotplug_interrupts(struct analogix_dp_device *dp);
>>   void analogix_dp_reset_aux(struct analogix_dp_device *dp);
>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
>> index 21a3287..c7e2959 100644
>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
>> @@ -365,6 +365,15 @@ void analogix_dp_init_hpd(struct analogix_dp_device *dp)
>>   	writel(reg, dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
>>   }
>>   
>> +void analogix_dp_force_hpd(struct analogix_dp_device *dp)
>> +{
>> +	u32 reg;
>> +
>> +	reg = readl(dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
>> +	reg = (F_HPD | HPD_CTRL);
>> +	writel(reg, dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
>> +}
>> +
>>   enum dp_irq_type analogix_dp_get_irq_type(struct analogix_dp_device *dp)
>>   {
>>   	u32 reg;
>> -- 
>> 1.9.1
>>
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>
>

Patch
diff mbox

diff --git a/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt b/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
index 7659a7a..4f2ba8c 100644
--- a/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
+++ b/Documentation/devicetree/bindings/display/bridge/analogix_dp.txt
@@ -22,6 +22,9 @@  Required properties for dp-controller:
 		from general PHY binding: Should be "dp".
 
 Optional properties for dp-controller:
+	-force-hpd:
+		Indicate driver need force hpd when hpd detect failed, this
+		is used for some eDP screen which don't have hpd signal.
 	-hpd-gpios:
 		Hotplug detect GPIO.
 		Indicates which GPIO should be used for hotplug detection
@@ -31,7 +34,6 @@  Optional properties for dp-controller:
 		* Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
 		* Documentation/devicetree/bindings/video/analogix_dp-rockchip.txt
 
-
 [1]: Documentation/devicetree/bindings/media/video-interfaces.txt
 -------------------------------------------------------------------------------
 
diff --git a/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt b/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
index 9905081..8800164 100644
--- a/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
+++ b/Documentation/devicetree/bindings/display/exynos/exynos_dp.txt
@@ -41,6 +41,7 @@  For the below properties, please refer to Analogix DP binding document:
 	-phys (required)
 	-phy-names (required)
 	-hpd-gpios (optional)
+	-analogix,need-force-hpd (optional)
 	-video interfaces (optional)
 
 Deprecated properties for DisplayPort:
diff --git a/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt b/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
index dae86c4..187a708e 100644
--- a/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
+++ b/Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt
@@ -32,6 +32,7 @@  For the below properties, please refer to Analogix DP binding document:
 - phys (required)
 - phy-names (required)
 - hpd-gpios (optional)
+- force-hpd (optional)
 -------------------------------------------------------------------------------
 
 Example:
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index a11504b..00aee44 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -59,15 +59,38 @@  static int analogix_dp_detect_hpd(struct analogix_dp_device *dp)
 {
 	int timeout_loop = 0;
 
-	while (analogix_dp_get_plug_in_status(dp) != 0) {
+	while (timeout_loop < DP_TIMEOUT_LOOP_COUNT) {
+		if (analogix_dp_get_plug_in_status(dp) == 0)
+			return 0;
+
 		timeout_loop++;
-		if (timeout_loop > DP_TIMEOUT_LOOP_COUNT) {
-			dev_err(dp->dev, "failed to get hpd plug status\n");
-			return -ETIMEDOUT;
-		}
 		usleep_range(10, 11);
 	}
 
+	/*
+	 * Some edp screen do not have hpd signal, so we can't just
+	 * return failed when hpd plug in detect failed, DT property
+	 * "need-force-hpd" would indicate whether driver need this.
+	 */
+	if (!dp->force_hpd)
+		return -ETIMEDOUT;
+
+	/*
+	 * The eDP TRM indicate that if HPD_STATUS(RO) is 0, AUX CH
+	 * will not work, so we need to give a force hpd action to
+	 * set HPD_STATUS manually.
+	 */
+	dev_dbg(dp->dev, "failed to get hpd plug status, try to force hpd\n");
+
+	analogix_dp_force_hpd(dp);
+
+	if (analogix_dp_get_plug_in_status(dp) != 0) {
+		dev_err(dp->dev, "failed to get hpd plug in status\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(dp->dev, "success to get plug in status after force hpd\n");
+
 	return 0;
 }
 
@@ -1246,6 +1269,8 @@  int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 	if (IS_ERR(dp->reg_base))
 		return PTR_ERR(dp->reg_base);
 
+	dp->force_hpd = of_property_read_bool(dev->of_node, "force-hpd");
+
 	dp->hpd_gpio = of_get_named_gpio(dev->of_node, "hpd-gpios", 0);
 	if (!gpio_is_valid(dp->hpd_gpio))
 		dp->hpd_gpio = of_get_named_gpio(dev->of_node,
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
index e6f8243..07e147c 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
@@ -160,6 +160,7 @@  struct analogix_dp_device {
 	struct phy		*phy;
 	int			dpms_mode;
 	int			hpd_gpio;
+	bool                    force_hpd;
 
 	struct analogix_dp_plat_data *plat_data;
 };
@@ -180,6 +181,7 @@  void analogix_dp_set_analog_power_down(struct analogix_dp_device *dp,
 				       bool enable);
 void analogix_dp_init_analog_func(struct analogix_dp_device *dp);
 void analogix_dp_init_hpd(struct analogix_dp_device *dp);
+void analogix_dp_force_hpd(struct analogix_dp_device *dp);
 enum dp_irq_type analogix_dp_get_irq_type(struct analogix_dp_device *dp);
 void analogix_dp_clear_hotplug_interrupts(struct analogix_dp_device *dp);
 void analogix_dp_reset_aux(struct analogix_dp_device *dp);
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
index 21a3287..c7e2959 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
@@ -365,6 +365,15 @@  void analogix_dp_init_hpd(struct analogix_dp_device *dp)
 	writel(reg, dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
 }
 
+void analogix_dp_force_hpd(struct analogix_dp_device *dp)
+{
+	u32 reg;
+
+	reg = readl(dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
+	reg = (F_HPD | HPD_CTRL);
+	writel(reg, dp->reg_base + ANALOGIX_DP_SYS_CTL_3);
+}
+
 enum dp_irq_type analogix_dp_get_irq_type(struct analogix_dp_device *dp)
 {
 	u32 reg;