[alsa-devel] [PATCH] ASoC: atmel-pcm-dma: increase buffer_bytes_max
atmel-pcm-dma is not limited to a buffer size of 64kB like atmel-pcm-pdc. Increase buffer_bytes_max to 512kB to allow for higher bit rates (i.e. 32bps at 192kHz) to work correctly. By default, keep the prealloc at 64kB.
Signed-off-by: Alexandre Belloni alexandre.belloni@free-electrons.com --- sound/soc/atmel/atmel-pcm-dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/soc/atmel/atmel-pcm-dma.c b/sound/soc/atmel/atmel-pcm-dma.c index b8e7bad05eb1..b6625c8c411b 100644 --- a/sound/soc/atmel/atmel-pcm-dma.c +++ b/sound/soc/atmel/atmel-pcm-dma.c @@ -54,7 +54,7 @@ static const struct snd_pcm_hardware atmel_pcm_dma_hardware = { .period_bytes_max = 2 * 0xffff, /* if 2 bytes format */ .periods_min = 8, .periods_max = 1024, /* no limit */ - .buffer_bytes_max = ATMEL_SSC_DMABUF_SIZE, + .buffer_bytes_max = 512 * 1024, };
/** @@ -119,7 +119,7 @@ static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream, static const struct snd_dmaengine_pcm_config atmel_dmaengine_pcm_config = { .prepare_slave_config = atmel_pcm_configure_dma, .pcm_hardware = &atmel_pcm_dma_hardware, - .prealloc_buffer_size = ATMEL_SSC_DMABUF_SIZE, + .prealloc_buffer_size = 64 * 1024, };
int atmel_pcm_dma_platform_register(struct device *dev)
On 03/30/2015 09:40 PM, Alexandre Belloni wrote:
atmel-pcm-dma is not limited to a buffer size of 64kB like atmel-pcm-pdc. Increase buffer_bytes_max to 512kB to allow for higher bit rates (i.e. 32bps at 192kHz) to work correctly. By default, keep the prealloc at 64kB.
Patch per se looks good. But can you test if it works to just throw atmel_pcm_dma_hardware away completely and rely on the dmaengine PCM driver getting the capabilities directly from the DMA driver. Since the DMA driver now reports its capabilities I think it should work, and if it does that's the preferred solution.
- Lars
On Mon, Mar 30, 2015 at 09:40:37PM +0200, Alexandre Belloni wrote:
atmel-pcm-dma is not limited to a buffer size of 64kB like atmel-pcm-pdc. Increase buffer_bytes_max to 512kB to allow for higher bit rates (i.e. 32bps at 192kHz) to work correctly. By default, keep the prealloc at 64kB.
Applied, but please look into Lars' suggestion - we should be able to just figure everything out from the DMA controller.
On 01/04/2015 at 21:33:42 +0100, Mark Brown wrote :
On Mon, Mar 30, 2015 at 09:40:37PM +0200, Alexandre Belloni wrote:
atmel-pcm-dma is not limited to a buffer size of 64kB like atmel-pcm-pdc. Increase buffer_bytes_max to 512kB to allow for higher bit rates (i.e. 32bps at 192kHz) to work correctly. By default, keep the prealloc at 64kB.
Applied, but please look into Lars' suggestion - we should be able to just figure everything out from the DMA controller.
This is definitively on the TODO list.
participants (3)
-
Alexandre Belloni -
Lars-Peter Clausen -
Mark Brown