[Intel-gfx] [PATCH] drm/i915/display: Trigger Modeset at boot for audio codec init

[Maarten Lankhorst]

Op 18-03-2020 om 15:37 schreef Shankar, Uma:
>
>> -----Original Message-----
>> From: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>> Sent: Wednesday, March 18, 2020 5:46 PM
>> To: Shankar, Uma <uma.shankar at intel.com>; intel-gfx at lists.freedesktop.org
>> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>; Kai Vehmanen
>> <kai.vehmanen at linux.intel.com>; Khor, Swee Aun <swee.aun.khor at intel.com>
>> Subject: Re: [PATCH] drm/i915/display: Trigger Modeset at boot for audio codec init
>>
>> Op 18-03-2020 om 12:30 schreef Uma Shankar:
>>> If external monitors are connected during boot up, driver uses the
>>> same mode programmed by BIOS and avoids a full modeset.
>>> This results in display audio codec left uninitialized and display
>>> audio fails to work till user triggers a modeset.
>>>
>>> This patch fixes the same by triggering a modeset at boot.
>>>
>>> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>>> Cc: Kai Vehmanen <kai.vehmanen at linux.intel.com>
>>> Signed-off-by: Uma Shankar <uma.shankar at intel.com>
>>> Signed-off-by: SweeAun Khor <swee.aun.khor at intel.com>
>>> ---
>>>  drivers/gpu/drm/i915/display/intel_ddi.c     | 4 ++++
>>>  drivers/gpu/drm/i915/display/intel_display.c | 8 ++++++++
>>>  drivers/gpu/drm/i915/i915_drv.h              | 3 +++
>>>  3 files changed, 15 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
>>> b/drivers/gpu/drm/i915/display/intel_ddi.c
>>> index 73d0f4648c06..ba380afa73a6 100644
>>> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
>>> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
>>> @@ -3704,6 +3704,10 @@ static void intel_ddi_update_pipe(struct intel_encoder
>> *encoder,
>>>  				  const struct intel_crtc_state *crtc_state,
>>>  				  const struct drm_connector_state *conn_state)  {
>>> +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
>>> +
>>> +	/* Clear the bootflag */
>>> +	dev_priv->bootflag = false;
>>>
>>>  	if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI))
>>>  		intel_ddi_update_pipe_dp(encoder, crtc_state, conn_state); diff
>>> --git a/drivers/gpu/drm/i915/display/intel_display.c
>>> b/drivers/gpu/drm/i915/display/intel_display.c
>>> index 8f23c4d51c33..a1487539495f 100644
>>> --- a/drivers/gpu/drm/i915/display/intel_display.c
>>> +++ b/drivers/gpu/drm/i915/display/intel_display.c
>>> @@ -14751,6 +14751,10 @@ static int intel_atomic_check(struct drm_device
>> *dev,
>>>  		if (new_crtc_state->hw.mode.private_flags !=
>>>  		    old_crtc_state->hw.mode.private_flags)
>>>  			new_crtc_state->uapi.mode_changed = true;
>>> +
>>> +		/* Set mode_change to init audio code once at boot */
>>> +		if (dev_priv->bootflag && new_crtc_state->hw.active)
>>> +			new_crtc_state->uapi.mode_changed = true;
>>>  	}
>>>
>>>  	ret = drm_atomic_helper_check_modeset(dev, &state->base); @@
>>> -17655,11 +17659,15 @@ static void intel_update_fdi_pll_freq(struct
>>> drm_i915_private *dev_priv)
>>>
>>>  static int intel_initial_commit(struct drm_device *dev)  {
>>> +	struct drm_i915_private *dev_priv = to_i915(dev);
>>>  	struct drm_atomic_state *state = NULL;
>>>  	struct drm_modeset_acquire_ctx ctx;
>>>  	struct intel_crtc *crtc;
>>>  	int ret = 0;
>>>
>>> +	/* Set Flag to trigger modeset for audio codec init */
>>> +	dev_priv->bootflag = true;
>>> +
>>>  	state = drm_atomic_state_alloc(dev);
>>>  	if (!state)
>>>  		return -ENOMEM;
>>> diff --git a/drivers/gpu/drm/i915/i915_drv.h
>>> b/drivers/gpu/drm/i915/i915_drv.h index a7ea1d855359..207196f9632b
>>> 100644
>>> --- a/drivers/gpu/drm/i915/i915_drv.h
>>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>>> @@ -1210,6 +1210,9 @@ struct drm_i915_private {
>>>  	 * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
>>>  	 * will be rejected. Instead look for a better place.
>>>  	 */
>>> +
>>> +	/* Flag to trigger modeset for Audio codec init once during boot */
>>> +	bool bootflag;
>>>  };
>>>
>>>  static inline struct drm_i915_private *to_i915(const struct
>>> drm_device *dev)
>> This is not going to help. We read out the has_audio flag now, the only thing we miss
>> is to enable the audio codec. This should be done after the first detect(), in the
>> manner which I described to get the correct eld values.
> Hi Maarten,
> At the time of sanitize, we don't have edid so has_audio flag will not be set. Also codec_enable
> needs encoder, crtc_state, conn_state. All these are not there as part of detect callbacks.

They can be used. You have connection_mutex, so you can look at connector->state,

if you then lock conn_state->crtc, you can inspect conn_state->crtc->state as well.

conn_state->encoder is available as well.

It needs some casting to get the intel_XX_state but you can do it safely.

~Maarten

> With current approach, we force a modeset just during boot and then reset the flag so that normal
> operations don't get affected.
>
> Regards,
> Uma Shankar
>
>> ~Maarten