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

[Khor, Swee Aun]

Hi Ville, 

You are right, your suggestion will fix this issue.

#Based on dmesg log, uapi mode private flags change is captured
...
[   11.404578] fbcon: i915drmfb (fb0) is primary device
[   11.404743] [drm] SA: intel_atomic_check: uapi change 
[   11.404744] [drm] SA2: intel_atomic_check: new_crtc_state->uapi.mode.private_flags= 0, old_crtc_state->uapi.mode.private_flags= 1  
[   11.404744] [drm] SA2: intel_atomic_check: new_crtc_state->uapi.mode.private_flags= 0, old_crtc_state->uapi.mode.private_flags= 0  
[   11.404745] [drm] SA2: intel_atomic_check: new_crtc_state->uapi.mode.private_flags= 0, old_crtc_state->uapi.mode.private_flags= 0  
[   11.404799] [drm:intel_atomic_check [i915]] [CONNECTOR:110:HDMI-A-2] Limiting display bpp to 24 instead of EDID bpp 24, requested bpp 36, max platform bpp 36
[   11.404855] [drm:intel_hdmi_compute_config [i915]] picking 8 bpc for HDMI output (pipe bpp: 24)
[   11.404898] [drm:intel_atomic_check [i915]] hw max bpp: 24, pipe bpp: 24, dithering: 0
...

#Here is the git diff 
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 4d1634ed6a1b..b5c56cd513d9 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -14108,11 +14108,15 @@ static int intel_atomic_check(struct drm_device *dev,
 	int ret, i;
 	bool any_ms = false;
 
+	DRM_INFO("SA: intel_atomic_check: uapi change \n");
+
 	/* Catch I915_MODE_FLAG_INHERITED */
 	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
 					    new_crtc_state, i) {
-		if (new_crtc_state->hw.mode.private_flags !=
-		    old_crtc_state->hw.mode.private_flags)
+
+		DRM_INFO("SA2: intel_atomic_check: new_crtc_state->uapi.mode.private_flags= %d, old_crtc_state->uapi.mode.private_flags= %d  \n", new_crtc_state->uapi.mode.private_flags, old_crtc_state->uapi.mode.private_flags );
+		if (new_crtc_state->uapi.mode.private_flags !=
+		    old_crtc_state->uapi.mode.private_flags)
 			new_crtc_state->uapi.mode_changed = true;
 	}

Regards,
SweeAun

-----Original Message-----
From: Khor, Swee Aun 
Sent: Saturday, March 21, 2020 12:55 AM
To: Ville Syrjälä <ville.syrjala at linux.intel.com>; Shankar, Uma <uma.shankar at intel.com>
Cc: Souza, Jose <jose.souza at intel.com>; intel-gfx at lists.freedesktop.org
Subject: RE: [Intel-gfx] [PATCH] drm/i915/display: Trigger Modeset at boot for audio codec init

Hi Ville,
You means this change right? Sure. Will try your suggestion as well. 
By the way, what is different between hw.mode and uapi.mode and how we know which to be used? It used to only base.mode before hw/uapi split patches. 

> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -14671,8 +14671,8 @@ static int intel_atomic_check(struct drm_device *dev,
>         /* Catch I915_MODE_FLAG_INHERITED */
>         for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
>                                             new_crtc_state, i) {
> -               if (new_crtc_state->hw.mode.private_flags !=
> -                   old_crtc_state->hw.mode.private_flags)
> +               if (new_crtc_state->uapi.mode.private_flags !=
> +                   old_crtc_state->uapi.mode.private_flags)
>                         new_crtc_state->uapi.mode_changed = true;
>         }
> 
> ?

Regards,
SweeAun

-----Original Message-----
From: Ville Syrjälä <ville.syrjala at linux.intel.com>
Sent: Friday, March 20, 2020 11:24 PM
To: Shankar, Uma <uma.shankar at intel.com>
Cc: Souza, Jose <jose.souza at intel.com>; intel-gfx at lists.freedesktop.org; Khor, Swee Aun <swee.aun.khor at intel.com>
Subject: Re: [Intel-gfx] [PATCH] drm/i915/display: Trigger Modeset at boot for audio codec init

On Fri, Mar 20, 2020 at 06:19:37AM +0000, Shankar, Uma wrote:
> 
> 
> > -----Original Message-----
> > From: Souza, Jose <jose.souza at intel.com>
> > Sent: Friday, March 20, 2020 12:36 AM
> > To: Shankar, Uma <uma.shankar at intel.com>; 
> > intel-gfx at lists.freedesktop.org
> > Cc: Khor, Swee Aun <swee.aun.khor at intel.com>
> > Subject: Re: [Intel-gfx] [PATCH] drm/i915/display: Trigger Modeset 
> > at boot for audio codec init
> > 
> > On Wed, 2020-03-18 at 17:00 +0530, Uma Shankar wrote:
> > > 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.
> > 
> > We had the same issue for PSR, take a look to the fix:
> > commit 33e059a2e4df454359f642f2235af39de9d3e914
> > drm/i915/psr: Force PSR probe only after full initialization
> > 
> > Maybe make this even more generic.
> 
> Yeah this looks to dealing with almost a similar need. Thanks for 
> pointing this out, will try to come up with a generalized solution.

How about just fixing the uapi vs. hw fail I showed instead of adding even more hacks?

--
Ville Syrjälä
Intel