linux-kernel - Re: [PATCH 3/3] tda998x: add HPD delay to avoid disabling sound when EDID checksum fails.

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Message-ID: <801ce163-b8ac-3375-56f2-9a8d7cd70ded@synopsys.com>
Date:	Tue, 31 May 2016 17:58:31 +0100
From:	Joao Pinto <Joao.Pinto@...opsys.com>
To:	Russell King - ARM Linux <linux@...linux.org.uk>,
	Joao Pinto <Joao.Pinto@...opsys.com>
CC:	<linux-kernel@...r.kernel.org>, <ijc+devicetree@...lion.org.uk>,
	<liviu.dudau@....com>, <ryan.harkin@...aro.org>
Subject: Re: [PATCH 3/3] tda998x: add HPD delay to avoid disabling sound when
 EDID checksum fails.

Hi Russell,

On 5/30/2016 8:10 PM, Russell King - ARM Linux wrote:
> On Mon, May 30, 2016 at 04:15:54PM +0100, Joao Pinto wrote:
>> When using ffplay to reproduce video+sound it was noticed that sometimes the
>> sound was disabled. The cause was an initial EDID checksum error that disabled

(...)

>> @@ -1313,6 +1324,7 @@ static int tda998x_create(struct i2c_client *client, struct tda998x_priv *priv)
>>  
>>  		/* init read EDID waitqueue and HDP work */
>>  		init_waitqueue_head(&priv->wq_edid);
>> +		INIT_DELAYED_WORK(&priv->dwork, tda998x_hpd);
>>  
>>  		/* clear pending interrupts */
>>  		reg_read(priv, REG_INT_FLAGS_0);
> 
> Clearly, this patch is incomplete.  There's nothing that schedules this
> work to be run.

You are right, forgot to include the schedule in the patch!

> 
> In any case, this is reintroducing the code which I deleted when I fixed
> the (rather crappy) previous implemention of delaying the EDID read after
> a hotplug event.  You should not need this patch.
> 

If a checksum validation fails the video reproduction is done muted if you use a
simple app like ffplay. This does not happen if using mplayer.

Could you please check the sound support patch?

Thanks,
Joao