Change to only call poweron/poweroff from atomic_enable/atomic_disable
ops instead of trying to keep a bridge_is_on state and poweron/off in
the hotplug irq handler.

A benefit of this is that drm mode_config mutex is always held at
poweron/off, something that may reduce the need for our own mutex.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 33 ++---------------------
 1 file changed, 2 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 9f2bc932c371..34bc6f4754b8 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -172,7 +172,6 @@ struct dw_hdmi {
 	enum drm_connector_force force;	/* mutex-protected force state */
 	struct drm_connector *curr_conn;/* current connector (only valid when !disabled) */
 	bool disabled;			/* DRM has disabled our bridge */
-	bool bridge_is_on;		/* indicates the bridge is on */
 	bool rxsense;			/* rxsense state */
 	u8 phy_mask;			/* desired phy int mask settings */
 	u8 mc_clkdis;			/* clock disable register */
@@ -2383,8 +2382,6 @@ static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi)
 
 static void dw_hdmi_poweron(struct dw_hdmi *hdmi)
 {
-	hdmi->bridge_is_on = true;
-
 	/*
 	 * The curr_conn field is guaranteed to be valid here, as this function
 	 * is only be called when !hdmi->disabled.
@@ -2398,30 +2395,6 @@ static void dw_hdmi_poweroff(struct dw_hdmi *hdmi)
 		hdmi->phy.ops->disable(hdmi, hdmi->phy.data);
 		hdmi->phy.enabled = false;
 	}
-
-	hdmi->bridge_is_on = false;
-}
-
-static void dw_hdmi_update_power(struct dw_hdmi *hdmi)
-{
-	int force = hdmi->force;
-
-	if (hdmi->disabled) {
-		force = DRM_FORCE_OFF;
-	} else if (force == DRM_FORCE_UNSPECIFIED) {
-		if (hdmi->rxsense)
-			force = DRM_FORCE_ON;
-		else
-			force = DRM_FORCE_OFF;
-	}
-
-	if (force == DRM_FORCE_OFF) {
-		if (hdmi->bridge_is_on)
-			dw_hdmi_poweroff(hdmi);
-	} else {
-		if (!hdmi->bridge_is_on)
-			dw_hdmi_poweron(hdmi);
-	}
 }
 
 /*
@@ -2546,7 +2519,6 @@ static void dw_hdmi_connector_force(struct drm_connector *connector)
 
 	mutex_lock(&hdmi->mutex);
 	hdmi->force = connector->force;
-	dw_hdmi_update_power(hdmi);
 	dw_hdmi_update_phy_mask(hdmi);
 	mutex_unlock(&hdmi->mutex);
 }
@@ -2955,7 +2927,7 @@ static void dw_hdmi_bridge_atomic_disable(struct drm_bridge *bridge,
 	mutex_lock(&hdmi->mutex);
 	hdmi->disabled = true;
 	hdmi->curr_conn = NULL;
-	dw_hdmi_update_power(hdmi);
+	dw_hdmi_poweroff(hdmi);
 	dw_hdmi_update_phy_mask(hdmi);
 	handle_plugged_change(hdmi, false);
 	mutex_unlock(&hdmi->mutex);
@@ -2974,7 +2946,7 @@ static void dw_hdmi_bridge_atomic_enable(struct drm_bridge *bridge,
 	mutex_lock(&hdmi->mutex);
 	hdmi->disabled = false;
 	hdmi->curr_conn = connector;
-	dw_hdmi_update_power(hdmi);
+	dw_hdmi_poweron(hdmi);
 	dw_hdmi_update_phy_mask(hdmi);
 	handle_plugged_change(hdmi, true);
 	mutex_unlock(&hdmi->mutex);
@@ -3073,7 +3045,6 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense)
 		if (hpd)
 			hdmi->rxsense = true;
 
-		dw_hdmi_update_power(hdmi);
 		dw_hdmi_update_phy_mask(hdmi);
 	}
 	mutex_unlock(&hdmi->mutex);
-- 
2.45.2

On 11/06/2024 17:50, Jonas Karlman wrote:
> Change to only call poweron/poweroff from atomic_enable/atomic_disable
> ops instead of trying to keep a bridge_is_on state and poweron/off in
> the hotplug irq handler.
> 
> A benefit of this is that drm mode_config mutex is always held at
> poweron/off, something that may reduce the need for our own mutex.
> 
> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
> ---
>   drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 33 ++---------------------
>   1 file changed, 2 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 9f2bc932c371..34bc6f4754b8 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -172,7 +172,6 @@ struct dw_hdmi {
>   	enum drm_connector_force force;	/* mutex-protected force state */
>   	struct drm_connector *curr_conn;/* current connector (only valid when !disabled) */
>   	bool disabled;			/* DRM has disabled our bridge */
> -	bool bridge_is_on;		/* indicates the bridge is on */
>   	bool rxsense;			/* rxsense state */
>   	u8 phy_mask;			/* desired phy int mask settings */
>   	u8 mc_clkdis;			/* clock disable register */
> @@ -2383,8 +2382,6 @@ static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi)
>   
>   static void dw_hdmi_poweron(struct dw_hdmi *hdmi)
>   {
> -	hdmi->bridge_is_on = true;
> -
>   	/*
>   	 * The curr_conn field is guaranteed to be valid here, as this function
>   	 * is only be called when !hdmi->disabled.
> @@ -2398,30 +2395,6 @@ static void dw_hdmi_poweroff(struct dw_hdmi *hdmi)
>   		hdmi->phy.ops->disable(hdmi, hdmi->phy.data);
>   		hdmi->phy.enabled = false;
>   	}
> -
> -	hdmi->bridge_is_on = false;
> -}
> -
> -static void dw_hdmi_update_power(struct dw_hdmi *hdmi)
> -{
> -	int force = hdmi->force;
> -
> -	if (hdmi->disabled) {
> -		force = DRM_FORCE_OFF;
> -	} else if (force == DRM_FORCE_UNSPECIFIED) {
> -		if (hdmi->rxsense)
> -			force = DRM_FORCE_ON;
> -		else
> -			force = DRM_FORCE_OFF;
> -	}

This means we always poweron the bridge even if rxsense is false ?

Neil

> -
> -	if (force == DRM_FORCE_OFF) {
> -		if (hdmi->bridge_is_on)
> -			dw_hdmi_poweroff(hdmi);
> -	} else {
> -		if (!hdmi->bridge_is_on)
> -			dw_hdmi_poweron(hdmi);
> -	}
>   }
>   
>   /*
> @@ -2546,7 +2519,6 @@ static void dw_hdmi_connector_force(struct drm_connector *connector)
>   
>   	mutex_lock(&hdmi->mutex);
>   	hdmi->force = connector->force;
> -	dw_hdmi_update_power(hdmi);
>   	dw_hdmi_update_phy_mask(hdmi);
>   	mutex_unlock(&hdmi->mutex);
>   }
> @@ -2955,7 +2927,7 @@ static void dw_hdmi_bridge_atomic_disable(struct drm_bridge *bridge,
>   	mutex_lock(&hdmi->mutex);
>   	hdmi->disabled = true;
>   	hdmi->curr_conn = NULL;
> -	dw_hdmi_update_power(hdmi);
> +	dw_hdmi_poweroff(hdmi);
>   	dw_hdmi_update_phy_mask(hdmi);
>   	handle_plugged_change(hdmi, false);
>   	mutex_unlock(&hdmi->mutex);
> @@ -2974,7 +2946,7 @@ static void dw_hdmi_bridge_atomic_enable(struct drm_bridge *bridge,
>   	mutex_lock(&hdmi->mutex);
>   	hdmi->disabled = false;
>   	hdmi->curr_conn = connector;
> -	dw_hdmi_update_power(hdmi);
> +	dw_hdmi_poweron(hdmi);
>   	dw_hdmi_update_phy_mask(hdmi);
>   	handle_plugged_change(hdmi, true);
>   	mutex_unlock(&hdmi->mutex);
> @@ -3073,7 +3045,6 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense)
>   		if (hpd)
>   			hdmi->rxsense = true;
>   
> -		dw_hdmi_update_power(hdmi);
>   		dw_hdmi_update_phy_mask(hdmi);
>   	}
>   	mutex_unlock(&hdmi->mutex);

Hi Neil,

On 2024-06-24 11:23, Neil Armstrong wrote:
> On 11/06/2024 17:50, Jonas Karlman wrote:
>> Change to only call poweron/poweroff from atomic_enable/atomic_disable
>> ops instead of trying to keep a bridge_is_on state and poweron/off in
>> the hotplug irq handler.
>>
>> A benefit of this is that drm mode_config mutex is always held at
>> poweron/off, something that may reduce the need for our own mutex.
>>
>> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
>> ---
>>   drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 33 ++---------------------
>>   1 file changed, 2 insertions(+), 31 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> index 9f2bc932c371..34bc6f4754b8 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> @@ -172,7 +172,6 @@ struct dw_hdmi {
>>   	enum drm_connector_force force;	/* mutex-protected force state */
>>   	struct drm_connector *curr_conn;/* current connector (only valid when !disabled) */
>>   	bool disabled;			/* DRM has disabled our bridge */
>> -	bool bridge_is_on;		/* indicates the bridge is on */
>>   	bool rxsense;			/* rxsense state */
>>   	u8 phy_mask;			/* desired phy int mask settings */
>>   	u8 mc_clkdis;			/* clock disable register */
>> @@ -2383,8 +2382,6 @@ static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi)
>>   
>>   static void dw_hdmi_poweron(struct dw_hdmi *hdmi)
>>   {
>> -	hdmi->bridge_is_on = true;
>> -
>>   	/*
>>   	 * The curr_conn field is guaranteed to be valid here, as this function
>>   	 * is only be called when !hdmi->disabled.
>> @@ -2398,30 +2395,6 @@ static void dw_hdmi_poweroff(struct dw_hdmi *hdmi)
>>   		hdmi->phy.ops->disable(hdmi, hdmi->phy.data);
>>   		hdmi->phy.enabled = false;
>>   	}
>> -
>> -	hdmi->bridge_is_on = false;
>> -}
>> -
>> -static void dw_hdmi_update_power(struct dw_hdmi *hdmi)
>> -{
>> -	int force = hdmi->force;
>> -
>> -	if (hdmi->disabled) {
>> -		force = DRM_FORCE_OFF;
>> -	} else if (force == DRM_FORCE_UNSPECIFIED) {
>> -		if (hdmi->rxsense)
>> -			force = DRM_FORCE_ON;
>> -		else
>> -			force = DRM_FORCE_OFF;
>> -	}
> 
> This means we always poweron the bridge even if rxsense is false ?

If I follow the logic there should not be any difference, beside that
power on now only happen in atomic_enable instead of sometime in irq
handler.

hdmi->rxsense is set to true based on hpd in dw_hdmi_setup_rx_sense().
For both meson and dw-hdmi this means HPD=1 and not rxsense=1.

drm core will call the force/detect ops and enable/disable based on
forced/HPD state, so I am not expecting any difference in how this
currently works.

This change to only poweron/setup in atomic_enable should also fix
issues/situations where dw-hdmi was poweron too early during bootup in
irq handler, before the drm driver was fully probed.

Regards,
Jonas

> 
> Neil
> 
>> -
>> -	if (force == DRM_FORCE_OFF) {
>> -		if (hdmi->bridge_is_on)
>> -			dw_hdmi_poweroff(hdmi);
>> -	} else {
>> -		if (!hdmi->bridge_is_on)
>> -			dw_hdmi_poweron(hdmi);
>> -	}
>>   }
>>   
>>   /*
>> @@ -2546,7 +2519,6 @@ static void dw_hdmi_connector_force(struct drm_connector *connector)
>>   
>>   	mutex_lock(&hdmi->mutex);
>>   	hdmi->force = connector->force;
>> -	dw_hdmi_update_power(hdmi);
>>   	dw_hdmi_update_phy_mask(hdmi);
>>   	mutex_unlock(&hdmi->mutex);
>>   }
>> @@ -2955,7 +2927,7 @@ static void dw_hdmi_bridge_atomic_disable(struct drm_bridge *bridge,
>>   	mutex_lock(&hdmi->mutex);
>>   	hdmi->disabled = true;
>>   	hdmi->curr_conn = NULL;
>> -	dw_hdmi_update_power(hdmi);
>> +	dw_hdmi_poweroff(hdmi);
>>   	dw_hdmi_update_phy_mask(hdmi);
>>   	handle_plugged_change(hdmi, false);
>>   	mutex_unlock(&hdmi->mutex);
>> @@ -2974,7 +2946,7 @@ static void dw_hdmi_bridge_atomic_enable(struct drm_bridge *bridge,
>>   	mutex_lock(&hdmi->mutex);
>>   	hdmi->disabled = false;
>>   	hdmi->curr_conn = connector;
>> -	dw_hdmi_update_power(hdmi);
>> +	dw_hdmi_poweron(hdmi);
>>   	dw_hdmi_update_phy_mask(hdmi);
>>   	handle_plugged_change(hdmi, true);
>>   	mutex_unlock(&hdmi->mutex);
>> @@ -3073,7 +3045,6 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense)
>>   		if (hpd)
>>   			hdmi->rxsense = true;
>>   
>> -		dw_hdmi_update_power(hdmi);
>>   		dw_hdmi_update_phy_mask(hdmi);
>>   	}
>>   	mutex_unlock(&hdmi->mutex);
>

On 24/06/2024 11:41, Jonas Karlman wrote:
> Hi Neil,
> 
> On 2024-06-24 11:23, Neil Armstrong wrote:
>> On 11/06/2024 17:50, Jonas Karlman wrote:
>>> Change to only call poweron/poweroff from atomic_enable/atomic_disable
>>> ops instead of trying to keep a bridge_is_on state and poweron/off in
>>> the hotplug irq handler.
>>>
>>> A benefit of this is that drm mode_config mutex is always held at
>>> poweron/off, something that may reduce the need for our own mutex.
>>>
>>> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
>>> ---
>>>    drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 33 ++---------------------
>>>    1 file changed, 2 insertions(+), 31 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>>> index 9f2bc932c371..34bc6f4754b8 100644
>>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>>> @@ -172,7 +172,6 @@ struct dw_hdmi {
>>>    	enum drm_connector_force force;	/* mutex-protected force state */
>>>    	struct drm_connector *curr_conn;/* current connector (only valid when !disabled) */
>>>    	bool disabled;			/* DRM has disabled our bridge */
>>> -	bool bridge_is_on;		/* indicates the bridge is on */
>>>    	bool rxsense;			/* rxsense state */
>>>    	u8 phy_mask;			/* desired phy int mask settings */
>>>    	u8 mc_clkdis;			/* clock disable register */
>>> @@ -2383,8 +2382,6 @@ static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi)
>>>    
>>>    static void dw_hdmi_poweron(struct dw_hdmi *hdmi)
>>>    {
>>> -	hdmi->bridge_is_on = true;
>>> -
>>>    	/*
>>>    	 * The curr_conn field is guaranteed to be valid here, as this function
>>>    	 * is only be called when !hdmi->disabled.
>>> @@ -2398,30 +2395,6 @@ static void dw_hdmi_poweroff(struct dw_hdmi *hdmi)
>>>    		hdmi->phy.ops->disable(hdmi, hdmi->phy.data);
>>>    		hdmi->phy.enabled = false;
>>>    	}
>>> -
>>> -	hdmi->bridge_is_on = false;
>>> -}
>>> -
>>> -static void dw_hdmi_update_power(struct dw_hdmi *hdmi)
>>> -{
>>> -	int force = hdmi->force;
>>> -
>>> -	if (hdmi->disabled) {
>>> -		force = DRM_FORCE_OFF;
>>> -	} else if (force == DRM_FORCE_UNSPECIFIED) {
>>> -		if (hdmi->rxsense)
>>> -			force = DRM_FORCE_ON;
>>> -		else
>>> -			force = DRM_FORCE_OFF;
>>> -	}
>>
>> This means we always poweron the bridge even if rxsense is false ?
> 
> If I follow the logic there should not be any difference, beside that
> power on now only happen in atomic_enable instead of sometime in irq
> handler.
> 
> hdmi->rxsense is set to true based on hpd in dw_hdmi_setup_rx_sense().
> For both meson and dw-hdmi this means HPD=1 and not rxsense=1.

Yeah I know, I was worried for other platforms using rxsense

> 
> drm core will call the force/detect ops and enable/disable based on
> forced/HPD state, so I am not expecting any difference in how this
> currently works.
> 
> This change to only poweron/setup in atomic_enable should also fix
> issues/situations where dw-hdmi was poweron too early during bootup in
> irq handler, before the drm driver was fully probed.

Hmm, but I thought the code wouldn't poweron the bridge is rxsense was 0
even if a mode was set, this won't work like this anymore right ?

Neil

> 
> Regards,
> Jonas
> 
>>
>> Neil
>>
>>> -
>>> -	if (force == DRM_FORCE_OFF) {
>>> -		if (hdmi->bridge_is_on)
>>> -			dw_hdmi_poweroff(hdmi);
>>> -	} else {
>>> -		if (!hdmi->bridge_is_on)
>>> -			dw_hdmi_poweron(hdmi);
>>> -	}
>>>    }
>>>    
>>>    /*
>>> @@ -2546,7 +2519,6 @@ static void dw_hdmi_connector_force(struct drm_connector *connector)
>>>    
>>>    	mutex_lock(&hdmi->mutex);
>>>    	hdmi->force = connector->force;
>>> -	dw_hdmi_update_power(hdmi);
>>>    	dw_hdmi_update_phy_mask(hdmi);
>>>    	mutex_unlock(&hdmi->mutex);
>>>    }
>>> @@ -2955,7 +2927,7 @@ static void dw_hdmi_bridge_atomic_disable(struct drm_bridge *bridge,
>>>    	mutex_lock(&hdmi->mutex);
>>>    	hdmi->disabled = true;
>>>    	hdmi->curr_conn = NULL;
>>> -	dw_hdmi_update_power(hdmi);
>>> +	dw_hdmi_poweroff(hdmi);
>>>    	dw_hdmi_update_phy_mask(hdmi);
>>>    	handle_plugged_change(hdmi, false);
>>>    	mutex_unlock(&hdmi->mutex);
>>> @@ -2974,7 +2946,7 @@ static void dw_hdmi_bridge_atomic_enable(struct drm_bridge *bridge,
>>>    	mutex_lock(&hdmi->mutex);
>>>    	hdmi->disabled = false;
>>>    	hdmi->curr_conn = connector;
>>> -	dw_hdmi_update_power(hdmi);
>>> +	dw_hdmi_poweron(hdmi);
>>>    	dw_hdmi_update_phy_mask(hdmi);
>>>    	handle_plugged_change(hdmi, true);
>>>    	mutex_unlock(&hdmi->mutex);
>>> @@ -3073,7 +3045,6 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense)
>>>    		if (hpd)
>>>    			hdmi->rxsense = true;
>>>    
>>> -		dw_hdmi_update_power(hdmi);
>>>    		dw_hdmi_update_phy_mask(hdmi);
>>>    	}
>>>    	mutex_unlock(&hdmi->mutex);
>>
>

Hi Neil,

On 2024-06-24 11:56, neil.armstrong@linaro.org wrote:
> On 24/06/2024 11:41, Jonas Karlman wrote:
>> Hi Neil,
>>
>> On 2024-06-24 11:23, Neil Armstrong wrote:
>>> On 11/06/2024 17:50, Jonas Karlman wrote:
>>>> Change to only call poweron/poweroff from atomic_enable/atomic_disable
>>>> ops instead of trying to keep a bridge_is_on state and poweron/off in
>>>> the hotplug irq handler.
>>>>
>>>> A benefit of this is that drm mode_config mutex is always held at
>>>> poweron/off, something that may reduce the need for our own mutex.
>>>>
>>>> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
>>>> ---
>>>>    drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 33 ++---------------------
>>>>    1 file changed, 2 insertions(+), 31 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>>>> index 9f2bc932c371..34bc6f4754b8 100644
>>>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>>>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>>>> @@ -172,7 +172,6 @@ struct dw_hdmi {
>>>>    	enum drm_connector_force force;	/* mutex-protected force state */
>>>>    	struct drm_connector *curr_conn;/* current connector (only valid when !disabled) */
>>>>    	bool disabled;			/* DRM has disabled our bridge */
>>>> -	bool bridge_is_on;		/* indicates the bridge is on */
>>>>    	bool rxsense;			/* rxsense state */
>>>>    	u8 phy_mask;			/* desired phy int mask settings */
>>>>    	u8 mc_clkdis;			/* clock disable register */
>>>> @@ -2383,8 +2382,6 @@ static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi)
>>>>    
>>>>    static void dw_hdmi_poweron(struct dw_hdmi *hdmi)
>>>>    {
>>>> -	hdmi->bridge_is_on = true;
>>>> -
>>>>    	/*
>>>>    	 * The curr_conn field is guaranteed to be valid here, as this function
>>>>    	 * is only be called when !hdmi->disabled.
>>>> @@ -2398,30 +2395,6 @@ static void dw_hdmi_poweroff(struct dw_hdmi *hdmi)
>>>>    		hdmi->phy.ops->disable(hdmi, hdmi->phy.data);
>>>>    		hdmi->phy.enabled = false;
>>>>    	}
>>>> -
>>>> -	hdmi->bridge_is_on = false;
>>>> -}
>>>> -
>>>> -static void dw_hdmi_update_power(struct dw_hdmi *hdmi)
>>>> -{
>>>> -	int force = hdmi->force;
>>>> -
>>>> -	if (hdmi->disabled) {
>>>> -		force = DRM_FORCE_OFF;
>>>> -	} else if (force == DRM_FORCE_UNSPECIFIED) {
>>>> -		if (hdmi->rxsense)
>>>> -			force = DRM_FORCE_ON;
>>>> -		else
>>>> -			force = DRM_FORCE_OFF;
>>>> -	}
>>>
>>> This means we always poweron the bridge even if rxsense is false ?
>>
>> If I follow the logic there should not be any difference, beside that
>> power on now only happen in atomic_enable instead of sometime in irq
>> handler.
>>
>> hdmi->rxsense is set to true based on hpd in dw_hdmi_setup_rx_sense().
>> For both meson and dw-hdmi this means HPD=1 and not rxsense=1.
> 
> Yeah I know, I was worried for other platforms using rxsense

From what I can find only dw-hdmi.c and dw_hdmi_meson.c are caller of
dw_hdmi_setup_rx_sense(). For meson the same value is passed for both
hpd and rx_sense, everyone else hpd = HPD and rx_sense = RX_SENSE status.

My understanding and testing based on Rockchip has shown that rx_sense
has no significant impact before and after this change.

> 
>>
>> drm core will call the force/detect ops and enable/disable based on
>> forced/HPD state, so I am not expecting any difference in how this
>> currently works.
>>
>> This change to only poweron/setup in atomic_enable should also fix
>> issues/situations where dw-hdmi was poweron too early during bootup in
>> irq handler, before the drm driver was fully probed.

I may have been wrong here, there is a check for disabled here so it
should not have setup() before atomic_enable().

Still we should ensure configure happen in atomic_enable(). The
hpd_irq_event/hpd_notify calls will trigger a detect() and signal core
if the bridge should be enabled/disabled when connector status changes.

> 
> Hmm, but I thought the code wouldn't poweron the bridge is rxsense was 0
> even if a mode was set, this won't work like this anymore right ?

This is what I thought was happening, and the comment in code seem to
indicate that. However, the code only seem to care about HPD=1 status to
poweron() and possible both HPD=0 + RXSENSE=0 to poweroff().

To make matter more complex core also mainly care about detect() status
and most/all related drivers seem to only use the the HPD status.

So I would say that there should not be any changes in impact of the
rxsense signal.

Will also send a new patch in a v2 for dw_hdmi_irq() that may be related:

-		if (phy_stat & HDMI_PHY_HPD)
+		if ((intr_stat & HDMI_IH_PHY_STAT0_HPD) &&
+		    (phy_stat & HDMI_PHY_HPD))
			status = connector_status_connected;

or there may be a status_connected event triggered when rxsense goes
from 1 to 0 and a second one with status_disconnected shortly after when
hpd goes from 1 to 0 when the cable is removed.

Regards,
Jonas

> 
> Neil
> 
>>
>> Regards,
>> Jonas
>>
>>>
>>> Neil
>>>
>>>> -
>>>> -	if (force == DRM_FORCE_OFF) {
>>>> -		if (hdmi->bridge_is_on)
>>>> -			dw_hdmi_poweroff(hdmi);
>>>> -	} else {
>>>> -		if (!hdmi->bridge_is_on)
>>>> -			dw_hdmi_poweron(hdmi);
>>>> -	}
>>>>    }
>>>>    
>>>>    /*
>>>> @@ -2546,7 +2519,6 @@ static void dw_hdmi_connector_force(struct drm_connector *connector)
>>>>    
>>>>    	mutex_lock(&hdmi->mutex);
>>>>    	hdmi->force = connector->force;
>>>> -	dw_hdmi_update_power(hdmi);
>>>>    	dw_hdmi_update_phy_mask(hdmi);
>>>>    	mutex_unlock(&hdmi->mutex);
>>>>    }
>>>> @@ -2955,7 +2927,7 @@ static void dw_hdmi_bridge_atomic_disable(struct drm_bridge *bridge,
>>>>    	mutex_lock(&hdmi->mutex);
>>>>    	hdmi->disabled = true;
>>>>    	hdmi->curr_conn = NULL;
>>>> -	dw_hdmi_update_power(hdmi);
>>>> +	dw_hdmi_poweroff(hdmi);
>>>>    	dw_hdmi_update_phy_mask(hdmi);
>>>>    	handle_plugged_change(hdmi, false);
>>>>    	mutex_unlock(&hdmi->mutex);
>>>> @@ -2974,7 +2946,7 @@ static void dw_hdmi_bridge_atomic_enable(struct drm_bridge *bridge,
>>>>    	mutex_lock(&hdmi->mutex);
>>>>    	hdmi->disabled = false;
>>>>    	hdmi->curr_conn = connector;
>>>> -	dw_hdmi_update_power(hdmi);
>>>> +	dw_hdmi_poweron(hdmi);
>>>>    	dw_hdmi_update_phy_mask(hdmi);
>>>>    	handle_plugged_change(hdmi, true);
>>>>    	mutex_unlock(&hdmi->mutex);
>>>> @@ -3073,7 +3045,6 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense)
>>>>    		if (hpd)
>>>>    			hdmi->rxsense = true;
>>>>    
>>>> -		dw_hdmi_update_power(hdmi);
>>>>    		dw_hdmi_update_phy_mask(hdmi);
>>>>    	}
>>>>    	mutex_unlock(&hdmi->mutex);
>>>
>>
>

On Mon, Jun 24, 2024 at 02:19:36PM +0200, Jonas Karlman wrote:
> Hi Neil,
> 
> On 2024-06-24 11:56, neil.armstrong@linaro.org wrote:
> > On 24/06/2024 11:41, Jonas Karlman wrote:
> >> Hi Neil,
> >>
> >> On 2024-06-24 11:23, Neil Armstrong wrote:
> >>> On 11/06/2024 17:50, Jonas Karlman wrote:
> >>>> Change to only call poweron/poweroff from atomic_enable/atomic_disable
> >>>> ops instead of trying to keep a bridge_is_on state and poweron/off in
> >>>> the hotplug irq handler.
> >>>>
> >>>> A benefit of this is that drm mode_config mutex is always held at
> >>>> poweron/off, something that may reduce the need for our own mutex.
> >>>>
> >>>> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
> >>>> ---
> >>>>    drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 33 ++---------------------
> >>>>    1 file changed, 2 insertions(+), 31 deletions(-)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> >>>> index 9f2bc932c371..34bc6f4754b8 100644
> >>>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> >>>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> >>>> @@ -172,7 +172,6 @@ struct dw_hdmi {
> >>>>    	enum drm_connector_force force;	/* mutex-protected force state */
> >>>>    	struct drm_connector *curr_conn;/* current connector (only valid when !disabled) */
> >>>>    	bool disabled;			/* DRM has disabled our bridge */
> >>>> -	bool bridge_is_on;		/* indicates the bridge is on */
> >>>>    	bool rxsense;			/* rxsense state */
> >>>>    	u8 phy_mask;			/* desired phy int mask settings */
> >>>>    	u8 mc_clkdis;			/* clock disable register */
> >>>> @@ -2383,8 +2382,6 @@ static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi)
> >>>>    
> >>>>    static void dw_hdmi_poweron(struct dw_hdmi *hdmi)
> >>>>    {
> >>>> -	hdmi->bridge_is_on = true;
> >>>> -
> >>>>    	/*
> >>>>    	 * The curr_conn field is guaranteed to be valid here, as this function
> >>>>    	 * is only be called when !hdmi->disabled.
> >>>> @@ -2398,30 +2395,6 @@ static void dw_hdmi_poweroff(struct dw_hdmi *hdmi)
> >>>>    		hdmi->phy.ops->disable(hdmi, hdmi->phy.data);
> >>>>    		hdmi->phy.enabled = false;
> >>>>    	}
> >>>> -
> >>>> -	hdmi->bridge_is_on = false;
> >>>> -}
> >>>> -
> >>>> -static void dw_hdmi_update_power(struct dw_hdmi *hdmi)
> >>>> -{
> >>>> -	int force = hdmi->force;
> >>>> -
> >>>> -	if (hdmi->disabled) {
> >>>> -		force = DRM_FORCE_OFF;
> >>>> -	} else if (force == DRM_FORCE_UNSPECIFIED) {
> >>>> -		if (hdmi->rxsense)
> >>>> -			force = DRM_FORCE_ON;
> >>>> -		else
> >>>> -			force = DRM_FORCE_OFF;
> >>>> -	}
> >>>
> >>> This means we always poweron the bridge even if rxsense is false ?
> >>
> >> If I follow the logic there should not be any difference, beside that
> >> power on now only happen in atomic_enable instead of sometime in irq
> >> handler.
> >>
> >> hdmi->rxsense is set to true based on hpd in dw_hdmi_setup_rx_sense().
> >> For both meson and dw-hdmi this means HPD=1 and not rxsense=1.
> > 
> > Yeah I know, I was worried for other platforms using rxsense
> 
> From what I can find only dw-hdmi.c and dw_hdmi_meson.c are caller of
> dw_hdmi_setup_rx_sense(). For meson the same value is passed for both
> hpd and rx_sense, everyone else hpd = HPD and rx_sense = RX_SENSE status.
> 
> My understanding and testing based on Rockchip has shown that rx_sense
> has no significant impact before and after this change.
> 
> > 
> >>
> >> drm core will call the force/detect ops and enable/disable based on
> >> forced/HPD state, so I am not expecting any difference in how this
> >> currently works.
> >>
> >> This change to only poweron/setup in atomic_enable should also fix
> >> issues/situations where dw-hdmi was poweron too early during bootup in
> >> irq handler, before the drm driver was fully probed.
> 
> I may have been wrong here, there is a check for disabled here so it
> should not have setup() before atomic_enable().
> 
> Still we should ensure configure happen in atomic_enable(). The
> hpd_irq_event/hpd_notify calls will trigger a detect() and signal core
> if the bridge should be enabled/disabled when connector status changes.
> 
> > 
> > Hmm, but I thought the code wouldn't poweron the bridge is rxsense was 0
> > even if a mode was set, this won't work like this anymore right ?
> 
> This is what I thought was happening, and the comment in code seem to
> indicate that. However, the code only seem to care about HPD=1 status to
> poweron() and possible both HPD=0 + RXSENSE=0 to poweroff().

More fundamental question: Why do we even care what happens in this case?
Userspace lit up an output that's not connected either

- it's broken, it gets to keep to pieces

- it knows what it's doing, there is a display, it's just broken, and it
  _really_ wants the output to be lit up.

Drivers trying to be clever isn't a good idea here imo ...
-Sima

> To make matter more complex core also mainly care about detect() status
> and most/all related drivers seem to only use the the HPD status.
> 
> So I would say that there should not be any changes in impact of the
> rxsense signal.
> 
> Will also send a new patch in a v2 for dw_hdmi_irq() that may be related:
> 
> -		if (phy_stat & HDMI_PHY_HPD)
> +		if ((intr_stat & HDMI_IH_PHY_STAT0_HPD) &&
> +		    (phy_stat & HDMI_PHY_HPD))
> 			status = connector_status_connected;
> 
> or there may be a status_connected event triggered when rxsense goes
> from 1 to 0 and a second one with status_disconnected shortly after when
> hpd goes from 1 to 0 when the cable is removed.
> 
> Regards,
> Jonas
> 
> > 
> > Neil
> > 
> >>
> >> Regards,
> >> Jonas
> >>
> >>>
> >>> Neil
> >>>
> >>>> -
> >>>> -	if (force == DRM_FORCE_OFF) {
> >>>> -		if (hdmi->bridge_is_on)
> >>>> -			dw_hdmi_poweroff(hdmi);
> >>>> -	} else {
> >>>> -		if (!hdmi->bridge_is_on)
> >>>> -			dw_hdmi_poweron(hdmi);
> >>>> -	}
> >>>>    }
> >>>>    
> >>>>    /*
> >>>> @@ -2546,7 +2519,6 @@ static void dw_hdmi_connector_force(struct drm_connector *connector)
> >>>>    
> >>>>    	mutex_lock(&hdmi->mutex);
> >>>>    	hdmi->force = connector->force;
> >>>> -	dw_hdmi_update_power(hdmi);
> >>>>    	dw_hdmi_update_phy_mask(hdmi);
> >>>>    	mutex_unlock(&hdmi->mutex);
> >>>>    }
> >>>> @@ -2955,7 +2927,7 @@ static void dw_hdmi_bridge_atomic_disable(struct drm_bridge *bridge,
> >>>>    	mutex_lock(&hdmi->mutex);
> >>>>    	hdmi->disabled = true;
> >>>>    	hdmi->curr_conn = NULL;
> >>>> -	dw_hdmi_update_power(hdmi);
> >>>> +	dw_hdmi_poweroff(hdmi);
> >>>>    	dw_hdmi_update_phy_mask(hdmi);
> >>>>    	handle_plugged_change(hdmi, false);
> >>>>    	mutex_unlock(&hdmi->mutex);
> >>>> @@ -2974,7 +2946,7 @@ static void dw_hdmi_bridge_atomic_enable(struct drm_bridge *bridge,
> >>>>    	mutex_lock(&hdmi->mutex);
> >>>>    	hdmi->disabled = false;
> >>>>    	hdmi->curr_conn = connector;
> >>>> -	dw_hdmi_update_power(hdmi);
> >>>> +	dw_hdmi_poweron(hdmi);
> >>>>    	dw_hdmi_update_phy_mask(hdmi);
> >>>>    	handle_plugged_change(hdmi, true);
> >>>>    	mutex_unlock(&hdmi->mutex);
> >>>> @@ -3073,7 +3045,6 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense)
> >>>>    		if (hpd)
> >>>>    			hdmi->rxsense = true;
> >>>>    
> >>>> -		dw_hdmi_update_power(hdmi);
> >>>>    		dw_hdmi_update_phy_mask(hdmi);
> >>>>    	}
> >>>>    	mutex_unlock(&hdmi->mutex);
> >>>
> >>
> > 
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch