Messages in this thread |  | | | Date | Thu, 30 Jun 2011 17:04:02 +0200 | | From | Nicolas Ferre <> | | Subject | Re: [alsa-devel] [PATCH 1/5] ASoC: wm8731: rework power management |
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Le 30/06/2011 15:57, Nicolas Ferre : > 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. > >>> - preserve crystal oscillator across suspend/resume sequence: >>> enabled by default, it should be kept enabled on resume. >> >> This isn't what your code does... >> >>> 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)
Actually it is: if... != WM8731_SYSCLK_XTAL
> + reg |= 1 << 0x5; > + snd_soc_update_bits(codec, WM8731_PWR, 0x00ff, reg);
And maybe here a simple snd_soc_write() is sufficient...
> 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
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