[ALSA] usb-audio: use vmalloc for the PCM buffer (6207e51b) · Commits · 戴 / test

sound/usb/usbaudio.c

+44 −9

Original line number	Diff line number	Diff line
		@@ -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 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);
		}
		}

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