Re: [PATCH] ASoC: SOF: Intel: hda: unsolicited RIRB response

From: Takashi Iwai <tiwai@suse.de>
To: "Lu, Brent" <brent.lu@intel.com>
Cc: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>,
	"alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>,
	Pierre-Louis Bossart DRIVERS 
	<pierre-louis.bossart@linux.intel.com>,
	"authored:2/16=12%,added_lines:21/248=8%,removed_lines:5/84=6%,),Liam
	 Girdwood DRIVERS )" <lgirdwood@gmail.com>,
	"commit_signer:6/16=38%,authored:6/16=38%,added_lines:123/248=50%
	 ,removed_lines:36/84=43%,Kai Vehmanen DRIVERS )" 
	<kai.vehmanen@linux.intel.com>,
	"Daniel Baluta DRIVERS )" <daniel.baluta@nxp.com>,
	Mark Brown <broonie@kernel.org>, Jaroslav Kysela <perex@perex.cz>,
	Takashi Iwai <tiwai@suse.com>,
	"Rojewski, Cezary" <cezary.rojewski@intel.com>,
	Zhu Yingjiang <yingjiang.zhu@linux.intel.com>,
	Keyon Jie <yang.jie@linux.intel.com>,
	Bard Liao <yung-chuan.liao@linux.intel.com>,
	"sound-open-firmware@alsa-project.orgDRIVERS" 
	<sound-open-firmware@alsa-project.orgDRIVERS>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ASoC: SOF: Intel: hda: unsolicited RIRB response
Date: Thu, 11 Jun 2020 19:59:26 +0200	[thread overview]
Message-ID: <s5h5zbxeb5t.wl-tiwai@suse.de> (raw)
In-Reply-To: <DM6PR11MB4316108BCF449D52E49C7E4297800@DM6PR11MB4316.namprd11.prod.outlook.com>

On Thu, 11 Jun 2020 19:09:08 +0200,
Lu, Brent wrote:
> 
> > Hi Brent,
> > 
> > Thanks for the patch. Is this fix for a specific issue you're seeing?
> > If so, could you please give us some details about it?
> > 
> > Thanks,
> > Ranjani
> 
> Hi Ranjani,
> 
> It's reported to happen on GLK Chromebook 'Fleex' that sometimes it
> cannot output the audio stream to external display. The kernel is
> Chrome v4.14 branch. Following is the reproduce step provided by
> ODM but I could reproduce it simply running aplay or cras_test_client
> so I think it's not about the cable plug/unplug handling.
> 
> What steps will reproduce the problem?
> 1.      Play YouTube video on Chromebook and connect it to external monitor with Type C to DP dongle
> 2.      Press monitor power button to turn off the monitor
> 3.      Press monitor power button again to turn on the monitor
> 4.      Continue to play YouTube video and check audio playback
> 5.      No sound comes out from built-in speaker of external monitor when turn on external monitor
> 
> I added debug messages to print the RIRBWP register and realize that
> response could come between the read of RIRBWP in the
> snd_hdac_bus_update_rirb() function and the interrupt clear in the
> hda_dsp_stream_interrupt() function. The response is not handled but
> the interrupt is already cleared. It will cause timeout unless more
> responses coming to RIRB.

Now I noticed that the legacy driver already addressed it recently via
commit 6d011d5057ff
    ALSA: hda: Clear RIRB status before reading WP

We should have checked SOF at the same time, too...

thanks,

Takashi