Re: [PATCH v2] ASoC: fsl_ssi: Fix channel swap on playback start

From: Arnaud Mouiche <arnaud.mouiche@invoxia.com>
To: Fabio Estevam <festevam@gmail.com>, Caleb Crome <caleb@crome.org>
Cc: "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>,
	Sascha Hauer <kernel@pengutronix.de>, Timur Tabi <timur@tabi.org>,
	Nicolin Chen <nicoleotsuka@gmail.com>,
	Mark Brown <broonie@kernel.org>,
	Max Krummenacher <max.krummenacher@toradex.com>,
	Fabio Estevam <fabio.estevam@nxp.com>
Subject: Re: [PATCH v2] ASoC: fsl_ssi: Fix channel swap on playback start
Date: Tue, 4 Apr 2017 00:05:57 +0200	[thread overview]
Message-ID: <a572220b-5bbd-9e47-31c4-ba272c5d28e7@invoxia.com> (raw)
In-Reply-To: <CAOMZO5BiRrRurJUsLb_pgSEw+ByZSSg6b3sRz17tKUXT1wRaSw@mail.gmail.com>

Hello.

On 03/04/2017 23:53, Fabio Estevam wrote:
> Hi Caleb,
>
> On Mon, Apr 3, 2017 at 5:32 PM, Caleb Crome <caleb@crome.org> wrote:
>
>> This patch definitely breaks the i.mx6 channel alignment.  In fact it
>> breaks it so that the channels are never aligned properly.
>>
>> My test setup is as follows:
>> * Get vanilla kernel, tag v4.11-rc5

I'm also testing  on a imx6sl board on v4.11-rc5 vanilla.

The Patch break something. I'm not even able to to make two consecutives 
'aplay' in order to generate something correct  on the external SSI bus.
- boot
- aplay -D hw:1,0 -r 48000 -c 2 -f S16_LE /dev/urandom
Playing raw data '/dev/urandom' : Signed 16 bit Little Endian, Rate 
48000 Hz, Stereo
^CAborted by signal Interrupt...

=> ok

- aplay -D hw:1,0 -r 48000 -c 2 -f S16_LE /dev/urandom
Playing raw data '/dev/urandom' : Signed 16 bit Little Endian, Rate 
48000 Hz, Stereo
aplay: pcm_write:1702: write error: Input/output error

=> no clock on external bus.

I confirm it works correctly without the patch.
On my board, the SSI device hw:1,0 is master of the bus (clock and sync) 
and is working in DSP mode.

I will continue the tests tomorrow.

Arnaud