Re: [PATCH 2/5] drm: Use new mode_valid() helpers in connector probe helper

[Jose Abreu]

Hi Ville,


On 04-05-2017 15:32, Ville Syrjälä wrote:
> On Thu, May 04, 2017 at 03:11:39PM +0100, Jose Abreu wrote:
>> This changes the connector probe helper function to use the new
>> encoder->mode_valid() and crtc->mode_valid() helper callbacks to
>> validate the modes.
>>
>> The new callbacks are optional so the behaviour remains the same
>> if they are not implemented. If they are, then the code loops
>> through all the connector's encodersXcrtcs and calls the
>> callback.
>>
>> If at least a valid encoderXcrtc combination is found which
>> accepts the mode then the function returns MODE_OK.
>>
>> Signed-off-by: Jose Abreu <joabreu@xxxxxxxxxxxx>
>> Cc: Carlos Palminha <palminha@xxxxxxxxxxxx>
>> Cc: Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
>> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
>> Cc: Dave Airlie <airlied@xxxxxxxx>
>> Cc: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
>> Cc: Archit Taneja <architt@xxxxxxxxxxxxxx>
>> ---
>>  drivers/gpu/drm/drm_probe_helper.c | 71 +++++++++++++++++++++++++++++++++++---
>>  1 file changed, 67 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
>> index 1b0c14a..bf19f82 100644
>> --- a/drivers/gpu/drm/drm_probe_helper.c
>> +++ b/drivers/gpu/drm/drm_probe_helper.c
>> @@ -80,6 +80,67 @@
>>  	return MODE_OK;
>>  }
>>  
>> +static enum drm_mode_status
>> +drm_mode_validate_connector(struct drm_connector *connector,
>> +			    struct drm_display_mode *mode)
>> +{
>> +	const struct drm_connector_helper_funcs *connector_funcs =
>> +		connector->helper_private;
>> +	struct drm_device *dev = connector->dev;
>> +	uint32_t *ids = connector->encoder_ids;
>> +	enum drm_mode_status ret = MODE_OK;
>> +	unsigned int i;
>> +
>> +	/* Step 1: Validate against connector */
>> +	if (connector_funcs && connector_funcs->mode_valid)
>> +		ret = connector_funcs->mode_valid(connector, mode);
>> +
>> +	if (ret != MODE_OK)
>> +		return ret;
>> +
>> +	/* Step 2: Validate against encoders and crtcs */
>> +	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
>> +		struct drm_encoder *encoder = drm_encoder_find(dev, ids[i]);
>> +		const struct drm_encoder_helper_funcs *encoder_funcs;
>> +		struct drm_crtc *crtc;
>> +
>> +		if (!encoder)
>> +			continue;
>> +
>> +		encoder_funcs = encoder->helper_private;
>> +		if (encoder_funcs && encoder_funcs->mode_valid)
>> +			ret = encoder_funcs->mode_valid(encoder, mode);
>> +		else
>> +			ret = MODE_OK; /* encoder accepts everything */
> Since you already added the drm_bridge_mode_valid() helper, maybe add one
> for connectors, encoders and crtcs as well. Might keep the logic in this
> function a bit more clear on account of not having to check for the
> presence of the vfunc. Right now all three cases look slightly
> different from one another.

Ok, will add in next version. Thanks!

Best regards,
Jose Miguel Abreu

>
>> +
>> +		/* No point in continuing for crtc check as this encoder will
>> +		 * not accept the mode anyway. If all encoders reject the mode
>> +		 * then, at exit, ret will not be MODE_OK. */
>> +		if (ret != MODE_OK)
>> +			continue;
>> +
>> +		drm_for_each_crtc(crtc, dev) {
>> +			const struct drm_crtc_helper_funcs *crtc_funcs;
>> +
>> +			if (!drm_encoder_crtc_ok(encoder, crtc))
>> +				continue;
>> +
>> +			crtc_funcs = crtc->helper_private;
>> +			if (!crtc_funcs || !crtc_funcs->mode_valid)
>> +				return MODE_OK; /* crtc accepts everything */
>> +
>> +			ret = crtc_funcs->mode_valid(crtc, mode);
>> +			if (ret == MODE_OK)
>> +				/* If we get to this point there is at least
>> +				 * one combination of encoder+crtc that works
>> +				 * for this mode. Lets return now. */
>> +				return ret;
>> +		}
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>>  static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
>>  {
>>  	struct drm_cmdline_mode *cmdline_mode;
>> @@ -283,8 +344,10 @@ void drm_kms_helper_poll_enable(struct drm_device *dev)
>>   *      (if specified)
>>   *    - drm_mode_validate_flag() checks the modes against basic connector
>>   *      capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
>> - *    - the optional &drm_connector_helper_funcs.mode_valid helper can perform
>> - *      driver and/or hardware specific checks
>> + *    - the optional &drm_connector_helper_funcs.mode_valid,
>> + *    	&drm_crtc_helper_funcs.mode_valid and
>> + *    	&drm_encoder_helper_funcs.mode_valid helpers can perform driver and/or
>> + *    	hardware specific checks
>>   *
>>   * 5. Any mode whose status is not OK is pruned from the connector's modes list,
>>   *    accompanied by a debug message indicating the reason for the mode's
>> @@ -428,8 +491,8 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
>>  		if (mode->status == MODE_OK)
>>  			mode->status = drm_mode_validate_flag(mode, mode_flags);
>>  
>> -		if (mode->status == MODE_OK && connector_funcs->mode_valid)
>> -			mode->status = connector_funcs->mode_valid(connector,
>> +		if (mode->status == MODE_OK)
>> +			mode->status = drm_mode_validate_connector(connector,
>>  								   mode);
>>  	}
>>  
>> -- 
>> 1.9.1
>>