Unverified Commit b0e3b0a7 authored by Sugar Zhang's avatar Sugar Zhang Committed by Mark Brown
Browse files

ASoC: dmaengine: Introduce module option prealloc_buffer_size_kbytes 



Currently, The fixed 512KB prealloc buffer size is too larger for
tiny memory kernel (such as 16MB memory). This patch adds the module
option "prealloc_buffer_size_kbytes" to specify prealloc buffer size.

It's suitable for cards which use the generic dmaengine pcm driver
with no config.

Signed-off-by: default avatarSugar Zhang <sugar.zhang@rock-chips.com>
Link: https://lore.kernel.org/r/1632394246-59341-1-git-send-email-sugar.zhang@rock-chips.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent d0900042

Documentation/sound/alsa-configuration.rst

+9 −0
Original line number Diff line number Diff line
@@ -100,6 +100,15 @@ amidi_map 
    MIDI device number maps assigned to the 2st OSS device;

    Default: 1



Module snd-soc-core

-------------------



The soc core module. It is used by all ALSA card drivers.

It takes the following options which have global effects.



prealloc_buffer_size_kbytes

    Specify prealloc buffer size in kbytes (default: 512).



Common parameters for top sound card modules

--------------------------------------------

sound/soc/soc-generic-dmaengine-pcm.c

+5 −1
Original line number Diff line number Diff line
@@ -15,6 +15,10 @@ 


#include <sound/dmaengine_pcm.h>



static unsigned int prealloc_buffer_size_kbytes = 512;

module_param(prealloc_buffer_size_kbytes, uint, 0444);

MODULE_PARM_DESC(prealloc_buffer_size_kbytes, "Preallocate DMA buffer size (KB).");



/*

 * The platforms dmaengine driver does not support reporting the amount of

 * bytes that are still left to transfer.
@@ -237,7 +241,7 @@ static int dmaengine_pcm_new(struct snd_soc_component *component, 
		prealloc_buffer_size = config->prealloc_buffer_size;

		max_buffer_size = config->pcm_hardware->buffer_bytes_max;

	} else {

		prealloc_buffer_size = 512 * 1024;

		prealloc_buffer_size = prealloc_buffer_size_kbytes * 1024;

		max_buffer_size = SIZE_MAX;

	}