From 6207e51b79f89352a8623f806df5bfafb012e489 Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Mon, 15 Aug 2005 08:35:25 +0200 Subject: [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 --- sound/usb/usbaudio.c | 53 +++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 44 insertions(+), 9 deletions(-) diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c index 13ff66b0a53..5aa5fe651a8 100644 --- a/sound/usb/usbaudio.c +++ b/sound/usb/usbaudio.c @@ -46,6 +46,7 @@ #include #include #include +#include #include #include #include @@ -676,6 +677,42 @@ static void snd_complete_sync_urb(struct urb *urb, struct pt_regs *regs) } +/* 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_substream_t *substream, 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_substream_t *substream) 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_playback = .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_capture = .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_ops = { .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_stream_t *as, int stream, struct audioformat 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_pcm_t *pcm) 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); } } -- cgit v1.2.3