[PATCH 2/4] drm: Make drm_encoder_helper_funcs optional

Noralf Trønnes noralf at tronnes.org
Mon May 9 19:19:22 UTC 2016


Den 05.05.2016 18:23, skrev Daniel Vetter:
> On Thu, May 05, 2016 at 03:24:32PM +0200, Noralf Trønnes wrote:
>> Make drm_encoder_helper_funcs and it's functions optional to avoid
>> having dummy functions.
>>
>> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
> Please also update the kerneldoc and mention there that the enable/disable
> hooks are optional. You can build the hmtl docs using

AFAICT the kerneldoc already says that they are optional for atomic helpers:

struct drm_encoder_helper_funcs {
[...]
         /**
          * @disable:
[...]
          * This hook is used both by legacy CRTC helpers and atomic 
helpers.
          * Atomic drivers don't need to implement it if there's no need to
          * disable anything at the encoder level. To ensure that runtime PM
[...]
         /**
          * @enable:
[...]
          * This hook is used only by atomic helpers, for symmetry with 
@disable.
          * Atomic drivers don't need to implement it if there's no need to
          * enable anything at the encoder level. To ensure that runtime 
PM handling

Noralf.

> $ make htmldocs
>
> to check the result. The vtables are documented in
> include/drm/drm_helper_vtables.h
>
>> ---
>>   drivers/gpu/drm/drm_atomic_helper.c | 11 ++++++++--
>>   drivers/gpu/drm/drm_crtc_helper.c   | 41 +++++++++++++++++++++++++++++--------
> Hm, tbh I wouldn't bother at all with crtc helpers and just drop that
> part. Old drivers should converted to atomic, new drivers should just use
> atomic. No need to touch that code at all.
> -Daniel
>
>>   2 files changed, 42 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
>> index 92e11a2..03ea049 100644
>> --- a/drivers/gpu/drm/drm_atomic_helper.c
>> +++ b/drivers/gpu/drm/drm_atomic_helper.c
>> @@ -696,6 +696,8 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
>>   			continue;
>>   
>>   		funcs = encoder->helper_private;
>> +		if (!funcs)
>> +			continue;
>>   
>>   		DRM_DEBUG_ATOMIC("disabling [ENCODER:%d:%s]\n",
>>   				 encoder->base.id, encoder->name);
>> @@ -711,7 +713,7 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
>>   			funcs->prepare(encoder);
>>   		else if (funcs->disable)
>>   			funcs->disable(encoder);
>> -		else
>> +		else if (funcs->dpms)
>>   			funcs->dpms(encoder, DRM_MODE_DPMS_OFF);
>>   
>>   		drm_bridge_post_disable(encoder->bridge);
>> @@ -859,6 +861,9 @@ crtc_set_mode(struct drm_device *dev, struct drm_atomic_state *old_state)
>>   
>>   		encoder = connector->state->best_encoder;
>>   		funcs = encoder->helper_private;
>> +		if (!funcs)
>> +			continue;
>> +
>>   		new_crtc_state = connector->state->crtc->state;
>>   		mode = &new_crtc_state->mode;
>>   		adjusted_mode = &new_crtc_state->adjusted_mode;
>> @@ -964,6 +969,8 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
>>   
>>   		encoder = connector->state->best_encoder;
>>   		funcs = encoder->helper_private;
>> +		if (!funcs)
>> +			continue;
>>   
>>   		DRM_DEBUG_ATOMIC("enabling [ENCODER:%d:%s]\n",
>>   				 encoder->base.id, encoder->name);
>> @@ -976,7 +983,7 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
>>   
>>   		if (funcs->enable)
>>   			funcs->enable(encoder);
>> -		else
>> +		else if (funcs->commit)
>>   			funcs->commit(encoder);
>>   
>>   		drm_bridge_enable(encoder->bridge);
>> diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
>> index 66ca313..6e6ab38 100644
>> --- a/drivers/gpu/drm/drm_crtc_helper.c
>> +++ b/drivers/gpu/drm/drm_crtc_helper.c
>> @@ -170,11 +170,14 @@ drm_encoder_disable(struct drm_encoder *encoder)
>>   {
>>   	const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
>>   
>> +	if (!encoder_funcs)
>> +		return;
>> +
>>   	drm_bridge_disable(encoder->bridge);
>>   
>>   	if (encoder_funcs->disable)
>>   		(*encoder_funcs->disable)(encoder);
>> -	else
>> +	else if (encoder_funcs->dpms)
>>   		(*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
>>   
>>   	drm_bridge_post_disable(encoder->bridge);
>> @@ -248,6 +251,9 @@ drm_crtc_prepare_encoders(struct drm_device *dev)
>>   
>>   	drm_for_each_encoder(encoder, dev) {
>>   		encoder_funcs = encoder->helper_private;
>> +		if (!encoder_funcs)
>> +			continue;
>> +
>>   		/* Disable unused encoders */
>>   		if (encoder->crtc == NULL)
>>   			drm_encoder_disable(encoder);
>> @@ -326,6 +332,10 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>   		if (encoder->crtc != crtc)
>>   			continue;
>>   
>> +		encoder_funcs = encoder->helper_private;
>> +		if (!encoder_funcs)
>> +			continue;
>> +
>>   		ret = drm_bridge_mode_fixup(encoder->bridge,
>>   			mode, adjusted_mode);
>>   		if (!ret) {
>> @@ -360,11 +370,15 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>   		if (encoder->crtc != crtc)
>>   			continue;
>>   
>> +		encoder_funcs = encoder->helper_private;
>> +		if (!encoder_funcs)
>> +			continue;
>> +
>>   		drm_bridge_disable(encoder->bridge);
>>   
>> -		encoder_funcs = encoder->helper_private;
>>   		/* Disable the encoders as the first thing we do. */
>> -		encoder_funcs->prepare(encoder);
>> +		if (encoder_funcs->prepare)
>> +			encoder_funcs->prepare(encoder);
>>   
>>   		drm_bridge_post_disable(encoder->bridge);
>>   	}
>> @@ -385,11 +399,15 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>   		if (encoder->crtc != crtc)
>>   			continue;
>>   
>> +		encoder_funcs = encoder->helper_private;
>> +		if (!encoder_funcs)
>> +			continue;
>> +
>>   		DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%d:%s]\n",
>>   			encoder->base.id, encoder->name,
>>   			mode->base.id, mode->name);
>> -		encoder_funcs = encoder->helper_private;
>> -		encoder_funcs->mode_set(encoder, mode, adjusted_mode);
>> +		if (encoder_funcs->mode_set)
>> +			encoder_funcs->mode_set(encoder, mode, adjusted_mode);
>>   
>>   		drm_bridge_mode_set(encoder->bridge, mode, adjusted_mode);
>>   	}
>> @@ -402,10 +420,14 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
>>   		if (encoder->crtc != crtc)
>>   			continue;
>>   
>> +		encoder_funcs = encoder->helper_private;
>> +		if (!encoder_funcs)
>> +			continue;
>> +
>>   		drm_bridge_pre_enable(encoder->bridge);
>>   
>> -		encoder_funcs = encoder->helper_private;
>> -		encoder_funcs->commit(encoder);
>> +		if (encoder_funcs->commit)
>> +			encoder_funcs->commit(encoder);
>>   
>>   		drm_bridge_enable(encoder->bridge);
>>   	}
>> @@ -771,12 +793,15 @@ static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
>>   	struct drm_bridge *bridge = encoder->bridge;
>>   	const struct drm_encoder_helper_funcs *encoder_funcs;
>>   
>> +	encoder_funcs = encoder->helper_private;
>> +	if (!encoder_funcs)
>> +		return;
>> +
>>   	if (mode == DRM_MODE_DPMS_ON)
>>   		drm_bridge_pre_enable(bridge);
>>   	else
>>   		drm_bridge_disable(bridge);
>>   
>> -	encoder_funcs = encoder->helper_private;
>>   	if (encoder_funcs->dpms)
>>   		encoder_funcs->dpms(encoder, mode);
>>   
>> -- 
>> 2.2.2
>>



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