tree 9fcf8208991a35a6bff0361858c94702bf5b4e76
parent 55851f734d7af7e5362d43b60331c95c32a3b027
author Clemens Ladisch <[EMAIL PROTECTED]> Mon, 15 Aug 2005 08:35:25 +0200
committer Jaroslav Kysela <[EMAIL PROTECTED]> Tue, 30 Aug 2005 08:45:57 +0200
[ALSA] usb-audio: use vmalloc for the PCM buffer
USB generic driver
With the double buffering, we no longer need contiguous memory for the
PCM buffer, so we can use vmalloc() instead of the preallocation
functions, and increase the maximum size to 256 KB.
Signed-off-by: Clemens Ladisch <[EMAIL PROTECTED]>
sound/usb/usbaudio.c | 53 ++++++++++++++++++++++++++++++++++++++++++---------
1 files changed, 44 insertions(+), 9 deletions(-)
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -46,6 +46,7 @@
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/usb.h>
+#include <linux/vmalloc.h>
#include <linux/moduleparam.h>
#include <sound/core.h>
#include <sound/info.h>
@@ -676,6 +677,42 @@ static void snd_complete_sync_urb(struct
}
+/* get the physical page pointer at the given offset */
+static struct page *snd_pcm_get_vmalloc_page(snd_pcm_substream_t *subs,
+ unsigned long offset)
+{
+ void *pageptr = subs->runtime->dma_area + offset;
+ return vmalloc_to_page(pageptr);
+}
+
+/* allocate virtual buffer; may be called more than once */
+static int snd_pcm_alloc_vmalloc_buffer(snd_pcm_substream_t *subs, size_t size)
+{
+ snd_pcm_runtime_t *runtime = subs->runtime;
+ if (runtime->dma_area) {
+ if (runtime->dma_bytes >= size)
+ return 0; /* already large enough */
+ vfree_nocheck(runtime->dma_area);
+ }
+ runtime->dma_area = vmalloc_nocheck(size);
+ if (! runtime->dma_area)
+ return -ENOMEM;
+ runtime->dma_bytes = size;
+ return 0;
+}
+
+/* free virtual buffer; may be called more than once */
+static int snd_pcm_free_vmalloc_buffer(snd_pcm_substream_t *subs)
+{
+ snd_pcm_runtime_t *runtime = subs->runtime;
+ if (runtime->dma_area) {
+ vfree_nocheck(runtime->dma_area);
+ runtime->dma_area = NULL;
+ }
+ return 0;
+}
+
+
/*
* unlink active urbs.
*/
@@ -1311,7 +1348,8 @@ static int snd_usb_hw_params(snd_pcm_sub
unsigned int channels, rate, format;
int ret, changed;
- ret = snd_pcm_lib_malloc_pages(substream,
params_buffer_bytes(hw_params));
+ ret = snd_pcm_alloc_vmalloc_buffer(substream,
+ params_buffer_bytes(hw_params));
if (ret < 0)
return ret;
@@ -1367,7 +1405,7 @@ static int snd_usb_hw_free(snd_pcm_subst
subs->cur_rate = 0;
subs->period_bytes = 0;
release_substream_urbs(subs, 0);
- return snd_pcm_lib_free_pages(substream);
+ return snd_pcm_free_vmalloc_buffer(substream);
}
/*
@@ -1406,7 +1444,7 @@ static snd_pcm_hardware_t snd_usb_playba
.info = (SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP_VALID),
- .buffer_bytes_max = (128*1024),
+ .buffer_bytes_max = (256*1024),
.period_bytes_min = 64,
.period_bytes_max = (128*1024),
.periods_min = 2,
@@ -1418,7 +1456,7 @@ static snd_pcm_hardware_t snd_usb_captur
.info = (SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP_VALID),
- .buffer_bytes_max = (128*1024),
+ .buffer_bytes_max = (256*1024),
.period_bytes_min = 64,
.period_bytes_max = (128*1024),
.periods_min = 2,
@@ -1810,6 +1848,7 @@ static snd_pcm_ops_t snd_usb_playback_op
.prepare = snd_usb_pcm_prepare,
.trigger = snd_usb_pcm_trigger,
.pointer = snd_usb_pcm_pointer,
+ .page = snd_pcm_get_vmalloc_page,
};
static snd_pcm_ops_t snd_usb_capture_ops = {
@@ -1821,6 +1860,7 @@ static snd_pcm_ops_t snd_usb_capture_ops
.prepare = snd_usb_pcm_prepare,
.trigger = snd_usb_pcm_trigger,
.pointer = snd_usb_pcm_pointer,
+ .page = snd_pcm_get_vmalloc_page,
};
@@ -2048,10 +2088,6 @@ static void init_substream(snd_usb_strea
subs->ops = audio_urb_ops[stream];
else
subs->ops = audio_urb_ops_high_speed[stream];
- snd_pcm_lib_preallocate_pages(as->pcm->streams[stream].substream,
- SNDRV_DMA_TYPE_CONTINUOUS,
- snd_dma_continuous_data(GFP_NOIO),
- 64 * 1024, 128 * 1024);
snd_pcm_set_ops(as->pcm, stream,
stream == SNDRV_PCM_STREAM_PLAYBACK ?
&snd_usb_playback_ops : &snd_usb_capture_ops);
@@ -2097,7 +2133,6 @@ static void snd_usb_audio_pcm_free(snd_p
snd_usb_stream_t *stream = pcm->private_data;
if (stream) {
stream->pcm = NULL;
- snd_pcm_lib_preallocate_free_for_all(pcm);
snd_usb_audio_stream_free(stream);
}
}
-
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