Unverified Commit 9d789dc0 authored by Peter Ujfalusi's avatar Peter Ujfalusi Committed by Mark Brown
Browse files

ALSA: dmaengine_pcm: Consider DMA cache caused delay in pointer callback 



Some DMA engines can have big FIFOs which adds to the latency.
The DMAengine framework can report the FIFO utilization in bytes. Use this
information for the delay reporting.

Signed-off-by: default avatarPeter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: default avatarTakashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200210153336.10218-1-peter.ujfalusi@ti.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent b56be800

sound/core/pcm_dmaengine.c

+2 −1
Original line number Diff line number Diff line
@@ -240,6 +240,7 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue); 
snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)

{

	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	struct snd_pcm_runtime *runtime = substream->runtime;

	struct dma_tx_state state;

	enum dma_status status;

	unsigned int buf_size;
@@ -257,7 +258,7 @@ snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream) 
						 state.in_flight_bytes);

	}



	return bytes_to_frames(substream->runtime, pos);

	return bytes_to_frames(runtime, pos);

}

EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);

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