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authorTakashi Iwai <tiwai@suse.de>2019-11-17 09:53:01 +0100
committerTakashi Iwai <tiwai@suse.de>2019-11-20 19:39:54 +0100
commit0dba808eae2627f40024872d2f02f75f0d2b0790 (patch)
treef558c21364d319e1625322d5529ea5bbb1db83fd /sound/core/pcm_native.c
parentc6ae99605633cade7dc61a2b35b04dda90302dad (diff)
ALSA: pcm: Introduce managed buffer allocation mode
This patch adds the support for the feature to automatically allocate and free PCM buffers, so called "managed buffer allocation" mode. It's set up via new PCM helpers, snd_pcm_set_managed_buffer() and snd_pcm_set_managed_buffer_all(), both of which correspond to the existing preallocator helpers, snd_pcm_lib_preallocate_pages() and snd_pcm_lib_preallocate_pages_for_all(). When the new helper is used, it not only performs the pre-allocation of buffers, but also it manages to call snd_pcm_lib_malloc_pages() before the PCM hw_params ops and snd_lib_pcm_free() after the PCM hw_free ops inside PCM core, respectively. This allows drivers to drop the explicit calls of the memory allocation / release functions, and it will be a good amount of code reduction in the end of this patch series. When the PCM substream is set to the managed buffer allocation mode, the managed_buffer_alloc flag is set in the substream object. Since some drivers want to know when a buffer is newly allocated or re-allocated at hw_params callback (e.g. want to set up the additional stuff for the given buffer only at allocation time), now PCM core turns on buffer_changed flag when the buffer has changed. The standard conversions to use the new API will be straightforward: - Replace snd_pcm_lib_preallocate*() calls with the corresponding snd_pcm_set_managed_buffer*(); the arguments should be unchanged - Drop superfluous snd_pcm_lib_malloc() and snd_pcm_lib_free() calls; the check of snd_pcm_lib_malloc() returns should be replaced with the check of runtime->buffer_changed flag. - If hw_params or hw_free becomes empty, drop them from PCM ops Link: https://lore.kernel.org/r/20191117085308.23915-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/pcm_native.c')
-rw-r--r--sound/core/pcm_native.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 0c27009dc3df..f1646735bde6 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -662,6 +662,14 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
if (err < 0)
goto _error;
+ if (substream->managed_buffer_alloc) {
+ err = snd_pcm_lib_malloc_pages(substream,
+ params_buffer_bytes(params));
+ if (err < 0)
+ goto _error;
+ runtime->buffer_changed = err > 0;
+ }
+
if (substream->ops->hw_params != NULL) {
err = substream->ops->hw_params(substream, params);
if (err < 0)
@@ -723,6 +731,8 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN);
if (substream->ops->hw_free != NULL)
substream->ops->hw_free(substream);
+ if (substream->managed_buffer_alloc)
+ snd_pcm_lib_free_pages(substream);
return err;
}
@@ -769,6 +779,8 @@ static int snd_pcm_hw_free(struct snd_pcm_substream *substream)
return -EBADFD;
if (substream->ops->hw_free)
result = substream->ops->hw_free(substream);
+ if (substream->managed_buffer_alloc)
+ snd_pcm_lib_free_pages(substream);
snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN);
pm_qos_remove_request(&substream->latency_pm_qos_req);
return result;