Commit d7dc9e32 authored by Markus Bollinger's avatar Markus Bollinger Committed by Takashi Iwai
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ALSA: pcxhr: Fix a counter wrap 



fix a counter wrap to avoid resynchronization of stream positions every several
minutes. The resynchronization may create stream position jitter

Signed-off-by: default avatarMarkus Bollinger <bollinger@digigram.com>

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent e0815f35

sound/pci/pcxhr/pcxhr_core.c

+15 −8
Original line number Diff line number Diff line
@@ -1133,13 +1133,12 @@ static u_int64_t pcxhr_stream_read_position(struct pcxhr_mgr *mgr, 
	hw_sample_count = ((u_int64_t)rmh.stat[0]) << 24;

	hw_sample_count += (u_int64_t)rmh.stat[1];



	snd_printdd("stream %c%d : abs samples real(%ld) timer(%ld)\n",

	snd_printdd("stream %c%d : abs samples real(%llu) timer(%llu)\n",

		    stream->pipe->is_capture ? 'C' : 'P',

		    stream->substream->number,

		    (long unsigned int)hw_sample_count,

		    (long unsigned int)(stream->timer_abs_periods +

					stream->timer_period_frag +

					mgr->granularity));

		    hw_sample_count,

		    stream->timer_abs_periods + stream->timer_period_frag +

						mgr->granularity);

	return hw_sample_count;

}
@@ -1243,11 +1242,19 @@ irqreturn_t pcxhr_interrupt(int irq, void *dev_id) 


		if ((dsp_time_diff < 0) &&

		    (mgr->dsp_time_last != PCXHR_DSP_TIME_INVALID)) {

			snd_printdd("ERROR DSP TIME old(%d) new(%d) -> "

				    "resynchronize all streams\n",

			/* handle dsp counter wraparound without resync */

			int tmp_diff = dsp_time_diff + PCXHR_DSP_TIME_MASK + 1;

			snd_printdd("WARNING DSP timestamp old(%d) new(%d)",

				    mgr->dsp_time_last, dsp_time_new);

			if (tmp_diff > 0 && tmp_diff <= (2*mgr->granularity)) {

				snd_printdd("-> timestamp wraparound OK: "

					    "diff=%d\n", tmp_diff);

				dsp_time_diff = tmp_diff;

			} else {

				snd_printdd("-> resynchronize all streams\n");

				mgr->dsp_time_err++;

			}

		}

#ifdef CONFIG_SND_DEBUG_VERBOSE

		if (dsp_time_diff == 0)

			snd_printdd("ERROR DSP TIME NO DIFF time(%d)\n",