Re: [alsa-devel] [PATCH 6/6] ASoC: davinci-mcasp: Add overrun/underrun event handling

On Mon, Nov 10, 2014 at 12:32:20PM +0200, Peter Ujfalusi wrote:

• stat = mcasp_get_reg(mcasp, DAVINCI_MCASP_TXSTAT_REG);
• if (stat & XUNDRN) {

• dev_warn(mcasp->dev, "Transmit buffer underflow\n");
  

• substream = mcasp->substreams[SNDRV_PCM_STREAM_PLAYBACK];
  

• if (substream) {
  

• 	snd_pcm_stream_lock_irq(substream);
  

• 	if (snd_pcm_running(substream))
  

• 		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
  

• 	snd_pcm_stream_unlock_irq(substream);
  

• }
  

• }
• mcasp_set_reg(mcasp, DAVINCI_MCASP_TXSTAT_REG, stat);
• return IRQ_HANDLED;

This will unconditionally report that any interrupt that gets delivered is handled and acknowledged regardles of what was reported. This isn't ideal, I'd at least expect a warning to be printed if we're handling interrupts we don't understand.