[PATCH] ARM: mach-imx6q: Enable the codec clock earlier

[troy.kisky@boundarydevices.com (Troy Kisky)]

On 6/7/2013 4:16 PM, Fabio Estevam wrote:
> Hi Russell,
>
> On Fri, Jun 7, 2013 at 7:20 PM, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
>
>> Umm... doesn't that mean that imx-sgtl5000 should be getting this clock
>> and turning it on itself, and disabling it on device removal?
> Yes, you are right.
>
> Actually imx-sgtl500 does get this clock and turn it on itself.
>
> The problem is that imx-sgtl5000 is getting called after the codec
> sgtl500 codec is probed.
>
> ***** reading codec ID
> sgtl5000: probe of 0-000a failed with error -5
> ***** enabling the codec clock
> imx-sgtl5000 sound.13: ASoC: CODEC (null) not registered
> imx-sgtl5000 sound.13: snd_soc_register_card failed (-517)
> platform sound.13: Driver imx-sgtl5000 requests probe deferral
>
>
> And then If I do:
>
> --- a/sound/soc/codecs/sgtl5000.c
> +++ b/sound/soc/codecs/sgtl5000.c
> @@ -1525,7 +1525,7 @@ static int sgtl5000_i2c_probe(struct i2c_client *client,
>          /* read chip information */
>          ret = regmap_read(sgtl5000->regmap, SGTL5000_CHIP_ID, &reg);
>          if (ret)
> -               return ret;
> +               return -EPROBE_DEFER;
>
>          if (((reg & SGTL5000_PARTID_MASK) >> SGTL5000_PARTID_SHIFT) !=
>              SGTL5000_PARTID_PART_ID) {
>
> Then the probe is succesful on the second attemp.
>
> I will post this to the alsa-devel list.
>
> Thanks,
>
> Fabio Estevam
>

Perhaps a delay is needed after the clock is turned on, to when you can 
read a register.

Using -EPROBE_DEFER seems like an abuse. Shouldn't it turn the clock 
back off before it returns anyway?

Troy