Le 29/06/2011 19:11, Mark Brown :

On Wed, Jun 29, 2011 at 08:00:15PM +0200, Nicolas Ferre wrote:

Don't mix multiple changes into a single patch!  There's no perceptible
code overlap between these so I don't understand why you've merged them,
it just makes review harder and the changelog less descriptive.

Ok.

quoted

- preserve crystal oscillator across suspend/resume sequence:
  enabled by default, it should be kept enabled on resume.

This isn't what your code does...

quoted

 		snd_soc_write(codec, WM8731_ACTIVE, 0x0);
-		snd_soc_write(codec, WM8731_PWR, 0xffff);
+		/* standby: keep crystal oscillator enabled */
+		snd_soc_write(codec, WM8731_PWR, 0x00df);

This doesn't keep the crystal oscillator enabled, this forces it on in
suspend (and without looking at the datasheet it also changes way more
than the one register bit I'd expect to be changed).  If the system
isn't using the oscillator then that's not good.

I'd expect to see a change to using snd_soc_update_bits() based on your
description, or more likely something more involved.

First of all, I experienced issues while not having OSC enabled during suspend/resume cycle. Am I right supposing that, if using oscillator to clock the codec, I have to keep it running during a suspend/resume cycle?

Is something like this sounds like an acceptable option or we need something more sophisticated?

@@ -481,7 +481,10 @@ static int wm8731_set_bias_level(struct snd_soc_codec *codec,
                break;
        case SND_SOC_BIAS_OFF:
                snd_soc_write(codec, WM8731_ACTIVE, 0x0);
-               snd_soc_write(codec, WM8731_PWR, 0xffff);
+               reg = 0xdf;
+               if (wm8731->sysclk_type == WM8731_SYSCLK_XTAL)
+                               reg |= 1 << 0x5;
+               snd_soc_update_bits(codec, WM8731_PWR, 0x00ff, reg);
                regulator_bulk_disable(ARRAY_SIZE(wm8731->supplies),
                                       wm8731->supplies);
                break;

And, yes, there is only 8 bits dedicated to power down control in this register.

Best regards,
-- 
Nicolas Ferre