On Wed, Apr 01, 2009 at 04:06:05PM +0200, Daniel Gl?ckner wrote: > On 04/01/2009 02:10 PM, Mark Brown wrote: > > Hrm, does the chip support asymmetric configurations for playback and > > capture? > No, why do you ask? In that case rather than using a trigger to check if the device is running it should be possible to use constraints to prevent reconfiguration of the device when it's not supported - this is more friendly to apps since they know they won't be allowed to change the configuration. > >> + * Enables or disables the left/right ADC/DAC according to new. > >> + * Bits in new: > > Is this really required? I can't see it being a good idea to bounce the > > power of the DAC or ADC while they are live since that will impact the > > audio stream noticably. It looks like it'd be better to do a check > > which refuses to do the reconfiguration when it's not possible. > Powering off is required in case the stream has been closed previously but the m close_delayed_work has not yet been run. That was the case where I observed the > problems this patch tries to fix. Eew, right. This should go in the comments. > > It's especially suspicious since the power of the DAC and ADC is managed > > via DAPM; the only current user should be safe since it saves then > > restores the state but it does raise alarm bells. > How about making it a function that always disables the four components and > referring to snd_soc_dapm_sync to restore the state? Hrm. For the ADC that's probably OK but powering off the DAC does risk being audible in the output; that does depend on the hardware, though. It should do the right thing, I think, but checking for audio artefacts would be advisable. It'd probably also help to only do reconfiguration if actually required rather than always powering down the ADCs and DACs. > In this version of the patch I removed the line that restores the state when > setting the sampling rate failed in-between. Is it safe to assume that DAPM will > not enable the ADC/DAC on other occasions before a valid sampling rate has been You should always get a chance to do a configuration before the DAC or ADC is enabled, yes. > configured? One could reorder aic3x_hw_params to detect the error before the > first registers are written.. Yes. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
