ASoC: DaVinci: pcm, fix underrun by using sram

Fix underruns by using dma to copy 1st to sram
in a ping/pong buffer style and then copying from
the sram to the ASP. This also has the advantage
of tolerating very long interrupt latency on dma
completion.
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

arch/arm/mach-davinci/include/mach/asp.h

@@ -57,6 +57,8 @@ struct snd_platform_data {
 	 * when compared to previous behavior.
 	 */
 	unsigned enable_channel_combine:1;
+	unsigned sram_size_playback;
+	unsigned sram_size_capture;
 
 	/* McASP specific fields */
 	int tdm_slots;

sound/soc/davinci/davinci-i2s.c

@@ -545,8 +545,13 @@ static int davinci_i2s_probe(struct platform_device *pdev)
 		ret = -ENOMEM;
 		goto err_release_region;
 	}
-	if (pdata)
+	if (pdata) {
 		dev->enable_channel_combine = pdata->enable_channel_combine;
+		dev->dma_params[SNDRV_PCM_STREAM_PLAYBACK].sram_size =
+			pdata->sram_size_playback;
+		dev->dma_params[SNDRV_PCM_STREAM_CAPTURE].sram_size =
+			pdata->sram_size_capture;
+	}
 	dev->clk = clk_get(&pdev->dev, NULL);
 	if (IS_ERR(dev->clk)) {
 		ret = -ENODEV;

sound/soc/davinci/davinci-pcm.c

@@ -3,6 +3,7 @@
  *
  * Author:      Vladimir Barinov, <vbarinov@embeddedalley.com>
  * Copyright:   (C) 2007 MontaVista Software, Inc., <source@mvista.com>
+ * added SRAM ping/pong (C) 2008 Troy Kisky <troy.kisky@boundarydevices.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -23,10 +24,51 @@
 
 #include <asm/dma.h>
 #include <mach/edma.h>
+#include <mach/sram.h>
 
 #include "davinci-pcm.h"
 
-static struct snd_pcm_hardware davinci_pcm_hardware = {
+#ifdef DEBUG
+static void print_buf_info(int slot, char *name)
+{
+	struct edmacc_param p;
+	if (slot < 0)
+		return;
+	edma_read_slot(slot, &p);
+	printk(KERN_DEBUG "%s: 0x%x, opt=%x, src=%x, a_b_cnt=%x dst=%x\n",
+			name, slot, p.opt, p.src, p.a_b_cnt, p.dst);
+	printk(KERN_DEBUG "    src_dst_bidx=%x link_bcntrld=%x src_dst_cidx=%x ccnt=%x\n",
+			p.src_dst_bidx, p.link_bcntrld, p.src_dst_cidx, p.ccnt);
+}
+#else
+static void print_buf_info(int slot, char *name)
+{
+}
+#endif
+
+static struct snd_pcm_hardware pcm_hardware_playback = {
+	.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
+		 SNDRV_PCM_INFO_PAUSE),
+	.formats = (SNDRV_PCM_FMTBIT_S16_LE),
+	.rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
+		  SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 |
+		  SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
+		  SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 |
+		  SNDRV_PCM_RATE_KNOT),
+	.rate_min = 8000,
+	.rate_max = 96000,
+	.channels_min = 2,
+	.channels_max = 2,
+	.buffer_bytes_max = 128 * 1024,
+	.period_bytes_min = 32,
+	.period_bytes_max = 8 * 1024,
+	.periods_min = 16,
+	.periods_max = 255,
+	.fifo_size = 0,
+};
+
+static struct snd_pcm_hardware pcm_hardware_capture = {
 	.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
 		 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
 		 SNDRV_PCM_INFO_PAUSE),
@@ -48,14 +90,58 @@ static struct snd_pcm_hardware davinci_pcm_hardware = {
 	.fifo_size = 0,
 };
 
+/*
+ * How ping/pong works....
+ *
+ * Playback:
+ * ram_params - copys 2*ping_size from start of SDRAM to iram,
+ * 	links to ram_link2
+ * ram_link2 - copys rest of SDRAM to iram in ping_size units,
+ * 	links to ram_link
+ * ram_link - copys entire SDRAM to iram in ping_size uints,
+ * 	links to self
+ *
+ * asp_params - same as asp_link[0]
+ * asp_link[0] - copys from lower half of iram to asp port
+ * 	links to asp_link[1], triggers iram copy event on completion
+ * asp_link[1] - copys from upper half of iram to asp port
+ * 	links to asp_link[0], triggers iram copy event on completion
+ * 	triggers interrupt only needed to let upper SOC levels update position
+ * 	in stream on completion
+ *
+ * When playback is started:
+ * 	ram_params started
+ * 	asp_params started
+ *
+ * Capture:
+ * ram_params - same as ram_link,
+ * 	links to ram_link
+ * ram_link - same as playback
+ * 	links to self
+ *
+ * asp_params - same as playback
+ * asp_link[0] - same as playback
+ * asp_link[1] - same as playback
+ *
+ * When capture is started:
+ * 	asp_params started
+ */
 struct davinci_runtime_data {
 	spinlock_t lock;
 	int period;		/* current DMA period */
 	int asp_channel;	/* Master DMA channel */
 	int asp_link[2];	/* asp parameter link channel, ping/pong */
 	struct davinci_pcm_dma_params *params;	/* DMA params */
+	int ram_channel;
+	int ram_link;
+	int ram_link2;
+	struct edmacc_param asp_params;
+	struct edmacc_param ram_params;
 };
 
+/*
+ * Not used with ping/pong
+ */
 static void davinci_pcm_enqueue_dma(struct snd_pcm_substream *substream)
 {
 	struct davinci_runtime_data *prtd = substream->runtime->private_data;
@@ -124,41 +210,290 @@ static void davinci_pcm_dma_irq(unsigned link, u16 ch_status, void *data)
 	struct snd_pcm_substream *substream = data;
 	struct davinci_runtime_data *prtd = substream->runtime->private_data;
 
+	print_buf_info(prtd->ram_channel, "i ram_channel");
 	pr_debug("davinci_pcm: link=%d, status=0x%x\n", link, ch_status);
 
 	if (unlikely(ch_status != DMA_COMPLETE))
 		return;
 
 	if (snd_pcm_running(substream)) {
-		snd_pcm_period_elapsed(substream);
-
+		if (prtd->ram_channel < 0) {
+			/* No ping/pong must fix up link dma data*/
 			spin_lock(&prtd->lock);
 			davinci_pcm_enqueue_dma(substream);
 			spin_unlock(&prtd->lock);
 		}
+		snd_pcm_period_elapsed(substream);
+	}
 }
 
-static int davinci_pcm_dma_request(struct snd_pcm_substream *substream)
+static int allocate_sram(struct snd_pcm_substream *substream, unsigned size,
+		struct snd_pcm_hardware *ppcm)
 {
-	struct davinci_runtime_data *prtd = substream->runtime->private_data;
+	struct snd_dma_buffer *buf = &substream->dma_buffer;
+	struct snd_dma_buffer *iram_dma = NULL;
+	dma_addr_t iram_phys = 0;
+	void *iram_virt = NULL;
+
+	if (buf->private_data || !size)
+		return 0;
+
+	ppcm->period_bytes_max = size;
+	iram_virt = sram_alloc(size, &iram_phys);
+	if (!iram_virt)
+		goto exit1;
+	iram_dma = kzalloc(sizeof(*iram_dma), GFP_KERNEL);
+	if (!iram_dma)
+		goto exit2;
+	iram_dma->area = iram_virt;
+	iram_dma->addr = iram_phys;
+	memset(iram_dma->area, 0, size);
+	iram_dma->bytes = size;
+	buf->private_data = iram_dma;
+	return 0;
+exit2:
+	if (iram_virt)
+		sram_free(iram_virt, size);
+exit1:
+	return -ENOMEM;
+}
+
+/*
+ * Only used with ping/pong.
+ * This is called after runtime->dma_addr, period_bytes and data_type are valid
+ */
+static int ping_pong_dma_setup(struct snd_pcm_substream *substream)
+{
+	unsigned short ram_src_cidx, ram_dst_cidx;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct davinci_runtime_data *prtd = runtime->private_data;
+	struct snd_dma_buffer *iram_dma =
+		(struct snd_dma_buffer *)substream->dma_buffer.private_data;
+	struct davinci_pcm_dma_params *params = prtd->params;
+	unsigned int data_type = params->data_type;
+	unsigned int acnt = params->acnt;
+	/* divide by 2 for ping/pong */
+	unsigned int ping_size = snd_pcm_lib_period_bytes(substream) >> 1;
+	int link = prtd->asp_link[1];
+	unsigned int fifo_level = prtd->params->fifo_level;
+	unsigned int count;
+	if ((data_type == 0) || (data_type > 4)) {
+		printk(KERN_ERR "%s: data_type=%i\n", __func__, data_type);
+		return -EINVAL;
+	}
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		dma_addr_t asp_src_pong = iram_dma->addr + ping_size;
+		ram_src_cidx = ping_size;
+		ram_dst_cidx = -ping_size;
+		edma_set_src(link, asp_src_pong, INCR, W8BIT);
+
+		link = prtd->asp_link[0];
+		edma_set_src_index(link, data_type, data_type * fifo_level);
+		link = prtd->asp_link[1];
+		edma_set_src_index(link, data_type, data_type * fifo_level);
+
+		link = prtd->ram_link;
+		edma_set_src(link, runtime->dma_addr, INCR, W32BIT);
+	} else {
+		dma_addr_t asp_dst_pong = iram_dma->addr + ping_size;
+		ram_src_cidx = -ping_size;
+		ram_dst_cidx = ping_size;
+		edma_set_dest(link, asp_dst_pong, INCR, W8BIT);
+
+		link = prtd->asp_link[0];
+		edma_set_dest_index(link, data_type, data_type * fifo_level);
+		link = prtd->asp_link[1];
+		edma_set_dest_index(link, data_type, data_type * fifo_level);
+
+		link = prtd->ram_link;
+		edma_set_dest(link, runtime->dma_addr, INCR, W32BIT);
+	}
+
+	if (!fifo_level) {
+		count = ping_size / data_type;
+		edma_set_transfer_params(prtd->asp_link[0], acnt, count,
+				1, 0, ASYNC);
+		edma_set_transfer_params(prtd->asp_link[1], acnt, count,
+				1, 0, ASYNC);
+	} else {
+		count = ping_size / (data_type * fifo_level);
+		edma_set_transfer_params(prtd->asp_link[0], acnt, fifo_level,
+				count, fifo_level, ABSYNC);
+		edma_set_transfer_params(prtd->asp_link[1], acnt, fifo_level,
+				count, fifo_level, ABSYNC);
+	}
+
+	link = prtd->ram_link;
+	edma_set_src_index(link, ping_size, ram_src_cidx);
+	edma_set_dest_index(link, ping_size, ram_dst_cidx);
+	edma_set_transfer_params(link, ping_size, 2,
+			runtime->periods, 2, ASYNC);
+
+	/* init master params */
+	edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
+	edma_read_slot(prtd->ram_link, &prtd->ram_params);
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		struct edmacc_param p_ram;
-	int ret;
+		/* Copy entire iram buffer before playback started */
+		prtd->ram_params.a_b_cnt = (1 << 16) | (ping_size << 1);
+		/* 0 dst_bidx */
+		prtd->ram_params.src_dst_bidx = (ping_size << 1);
+		/* 0 dst_cidx */
+		prtd->ram_params.src_dst_cidx = (ping_size << 1);
+		prtd->ram_params.ccnt = 1;
+
+		/* Skip 1st period */
+		edma_read_slot(prtd->ram_link, &p_ram);
+		p_ram.src += (ping_size << 1);
+		p_ram.ccnt -= 1;
+		edma_write_slot(prtd->ram_link2, &p_ram);
+		/*
+		 * When 1st started, ram -> iram dma channel will fill the
+		 * entire iram.  Then, whenever a ping/pong asp buffer finishes,
+		 * 1/2 iram will be filled.
+		 */
+		prtd->ram_params.link_bcntrld =
+			EDMA_CHAN_SLOT(prtd->ram_link2) << 5;
+	}
+	return 0;
+}
+
+/* 1 asp tx or rx channel using 2 parameter channels
+ * 1 ram to/from iram channel using 1 parameter channel
+ *
+ * Playback
+ * ram copy channel kicks off first,
+ * 1st ram copy of entire iram buffer completion kicks off asp channel
+ * asp tcc always kicks off ram copy of 1/2 iram buffer
+ *
+ * Record
+ * asp channel starts, tcc kicks off ram copy
+ */
+static int request_ping_pong(struct snd_pcm_substream *substream,
+		struct davinci_runtime_data *prtd,
+		struct snd_dma_buffer *iram_dma)
+{
+	dma_addr_t asp_src_ping;
+	dma_addr_t asp_dst_ping;
+	int link;
+	struct davinci_pcm_dma_params *params = prtd->params;
 
-	/* Request master DMA channel */
-	ret = edma_alloc_channel(prtd->params->channel,
+	/* Request ram master channel */
+	link = prtd->ram_channel = edma_alloc_channel(EDMA_CHANNEL_ANY,
 				  davinci_pcm_dma_irq, substream,
-				  EVENTQ_0);
-	if (ret < 0)
-		return ret;
-	prtd->asp_channel = ret;
+				  EVENTQ_1);
+	if (link < 0)
+		goto exit1;
+
+	/* Request ram link channel */
+	link = prtd->ram_link = edma_alloc_slot(
+			EDMA_CTLR(prtd->ram_channel), EDMA_SLOT_ANY);
+	if (link < 0)
+		goto exit2;
+
+	link = prtd->asp_link[1] = edma_alloc_slot(
+			EDMA_CTLR(prtd->asp_channel), EDMA_SLOT_ANY);
+	if (link < 0)
+		goto exit3;
+
+	prtd->ram_link2 = -1;
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		link = prtd->ram_link2 = edma_alloc_slot(
+			EDMA_CTLR(prtd->ram_channel), EDMA_SLOT_ANY);
+		if (link < 0)
+			goto exit4;
+	}
+	/* circle ping-pong buffers */
+	edma_link(prtd->asp_link[0], prtd->asp_link[1]);
+	edma_link(prtd->asp_link[1], prtd->asp_link[0]);
+	/* circle ram buffers */
+	edma_link(prtd->ram_link, prtd->ram_link);
 
-	/* Request parameter RAM reload slot */
-	ret = edma_alloc_slot(EDMA_CTLR(prtd->asp_channel), EDMA_SLOT_ANY);
-	if (ret < 0) {
-		edma_free_channel(prtd->asp_channel);
-		return ret;
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		asp_src_ping = iram_dma->addr;
+		asp_dst_ping = params->dma_addr;	/* fifo */
+	} else {
+		asp_src_ping = params->dma_addr;	/* fifo */
+		asp_dst_ping = iram_dma->addr;
+	}
+	/* ping */
+	link = prtd->asp_link[0];
+	edma_set_src(link, asp_src_ping, INCR, W16BIT);
+	edma_set_dest(link, asp_dst_ping, INCR, W16BIT);
+	edma_set_src_index(link, 0, 0);
+	edma_set_dest_index(link, 0, 0);
+
+	edma_read_slot(link, &prtd->asp_params);
+	prtd->asp_params.opt &= ~(TCCMODE | EDMA_TCC(0x3f) | TCINTEN);
+	prtd->asp_params.opt |= TCCHEN | EDMA_TCC(prtd->ram_channel & 0x3f);
+	edma_write_slot(link, &prtd->asp_params);
+
+	/* pong */
+	link = prtd->asp_link[1];
+	edma_set_src(link, asp_src_ping, INCR, W16BIT);
+	edma_set_dest(link, asp_dst_ping, INCR, W16BIT);
+	edma_set_src_index(link, 0, 0);
+	edma_set_dest_index(link, 0, 0);
+
+	edma_read_slot(link, &prtd->asp_params);
+	prtd->asp_params.opt &= ~(TCCMODE | EDMA_TCC(0x3f));
+	/* interrupt after every pong completion */
+	prtd->asp_params.opt |= TCINTEN | TCCHEN |
+		EDMA_TCC(EDMA_CHAN_SLOT(prtd->ram_channel));
+	edma_write_slot(link, &prtd->asp_params);
+
+	/* ram */
+	link = prtd->ram_link;
+	edma_set_src(link, iram_dma->addr, INCR, W32BIT);
+	edma_set_dest(link, iram_dma->addr, INCR, W32BIT);
+	pr_debug("%s: audio dma channels/slots in use for ram:%u %u %u,"
+		"for asp:%u %u %u\n", __func__,
+		prtd->ram_channel, prtd->ram_link, prtd->ram_link2,
+		prtd->asp_channel, prtd->asp_link[0],
+		prtd->asp_link[1]);
+	return 0;
+exit4:
+	edma_free_channel(prtd->asp_link[1]);
+	prtd->asp_link[1] = -1;
+exit3:
+	edma_free_channel(prtd->ram_link);
+	prtd->ram_link = -1;
+exit2:
+	edma_free_channel(prtd->ram_channel);
+	prtd->ram_channel = -1;
+exit1:
+	return link;
+}
+
+static int davinci_pcm_dma_request(struct snd_pcm_substream *substream)
+{
+	struct snd_dma_buffer *iram_dma;
+	struct davinci_runtime_data *prtd = substream->runtime->private_data;
+	struct davinci_pcm_dma_params *params = prtd->params;
+	int link;
+
+	if (!params)
+		return -ENODEV;
+
+	/* Request asp master DMA channel */
+	link = prtd->asp_channel = edma_alloc_channel(params->channel,
+			davinci_pcm_dma_irq, substream, EVENTQ_0);
+	if (link < 0)
+		goto exit1;
+
+	/* Request asp link channels */
+	link = prtd->asp_link[0] = edma_alloc_slot(
+			EDMA_CTLR(prtd->asp_channel), EDMA_SLOT_ANY);
+	if (link < 0)
+		goto exit2;
+
+	iram_dma = (struct snd_dma_buffer *)substream->dma_buffer.private_data;
+	if (iram_dma) {
+		if (request_ping_pong(substream, prtd, iram_dma) == 0)
+			return 0;
+		printk(KERN_WARNING "%s: dma channel allocation failed,"
+				"not using sram\n", __func__);
 	}
-	prtd->asp_link[0] = ret;
 
 	/* Issue transfer completion IRQ when the channel completes a
 	 * transfer, then always reload from the same slot (by a kind
@@ -169,12 +504,17 @@ static int davinci_pcm_dma_request(struct snd_pcm_substream *substream)
 	 * the buffer and its length (ccnt) ... use it as a template
 	 * so davinci_pcm_enqueue_dma() takes less time in IRQ.
 	 */
-	edma_read_slot(prtd->asp_link[0], &p_ram);
-	p_ram.opt |= TCINTEN | EDMA_TCC(EDMA_CHAN_SLOT(prtd->asp_channel));
-	p_ram.link_bcntrld = EDMA_CHAN_SLOT(prtd->asp_link[0]) << 5;
-	edma_write_slot(prtd->asp_link[0], &p_ram);
-
+	edma_read_slot(link, &prtd->asp_params);
+	prtd->asp_params.opt |= TCINTEN |
+		EDMA_TCC(EDMA_CHAN_SLOT(prtd->asp_channel));
+	prtd->asp_params.link_bcntrld = EDMA_CHAN_SLOT(link) << 5;
+	edma_write_slot(link, &prtd->asp_params);
 	return 0;
+exit2:
+	edma_free_channel(prtd->asp_channel);
+	prtd->asp_channel = -1;
+exit1:
+	return link;
 }
 
 static int davinci_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
@@ -208,14 +548,34 @@ static int davinci_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 static int davinci_pcm_prepare(struct snd_pcm_substream *substream)
 {
 	struct davinci_runtime_data *prtd = substream->runtime->private_data;
-	struct edmacc_param temp;
 
+	if (prtd->ram_channel >= 0) {
+		int ret = ping_pong_dma_setup(substream);
+		if (ret < 0)
+			return ret;
+
+		edma_write_slot(prtd->ram_channel, &prtd->ram_params);
+		edma_write_slot(prtd->asp_channel, &prtd->asp_params);
+
+		print_buf_info(prtd->ram_channel, "ram_channel");
+		print_buf_info(prtd->ram_link, "ram_link");
+		print_buf_info(prtd->ram_link2, "ram_link2");
+		print_buf_info(prtd->asp_channel, "asp_channel");
+		print_buf_info(prtd->asp_link[0], "asp_link[0]");
+		print_buf_info(prtd->asp_link[1], "asp_link[1]");
+
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+			/* copy 1st iram buffer */
+			edma_start(prtd->ram_channel);
+		}
+		return 0;
+	}
 	prtd->period = 0;
 	davinci_pcm_enqueue_dma(substream);
 
 	/* Copy self-linked parameter RAM entry into master channel */
-	edma_read_slot(prtd->asp_link[0], &temp);
-	edma_write_slot(prtd->asp_channel, &temp);
+	edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
+	edma_write_slot(prtd->asp_channel, &prtd->asp_params);
 	davinci_pcm_enqueue_dma(substream);
 
 	return 0;
@@ -231,13 +591,46 @@ davinci_pcm_pointer(struct snd_pcm_substream *substream)
 	dma_addr_t asp_src, asp_dst;
 
 	spin_lock(&prtd->lock);
-
+	if (prtd->ram_channel >= 0) {
+		int ram_count;
+		int mod_ram;
+		dma_addr_t ram_src, ram_dst;
+		unsigned int period_size = snd_pcm_lib_period_bytes(substream);
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+			/* reading ram before asp should be safe
+			 * as long as the asp transfers less than a ping size
+			 * of bytes between the 2 reads
+			 */
+			edma_get_position(prtd->ram_channel,
+					&ram_src, &ram_dst);
+			edma_get_position(prtd->asp_channel,
+					&asp_src, &asp_dst);
+			asp_count = asp_src - prtd->asp_params.src;
+			ram_count = ram_src - prtd->ram_params.src;
+			mod_ram = ram_count % period_size;
+			mod_ram -= asp_count;
+			if (mod_ram < 0)
+				mod_ram += period_size;
+			else if (mod_ram == 0) {
+				if (snd_pcm_running(substream))
+					mod_ram += period_size;
+			}
+			ram_count -= mod_ram;
+			if (ram_count < 0)
+				ram_count += period_size * runtime->periods;
+		} else {
+			edma_get_position(prtd->ram_channel,
+					&ram_src, &ram_dst);
+			ram_count = ram_dst - prtd->ram_params.dst;
+		}
+		asp_count = ram_count;
+	} else {
 		edma_get_position(prtd->asp_channel, &asp_src, &asp_dst);
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			asp_count = asp_src - runtime->dma_addr;
 		else
 			asp_count = asp_dst - runtime->dma_addr;
-
+	}
 	spin_unlock(&prtd->lock);
 
 	offset = bytes_to_frames(runtime, asp_count);
@@ -251,6 +644,7 @@ static int davinci_pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct davinci_runtime_data *prtd;
+	struct snd_pcm_hardware *ppcm;
 	int ret = 0;
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct davinci_pcm_dma_params *pa = rtd->dai->cpu_dai->dma_data;
@@ -259,7 +653,10 @@ static int davinci_pcm_open(struct snd_pcm_substream *substream)
 		return -ENODEV;
 	params = &pa[substream->stream];
 
-	snd_soc_set_runtime_hwparams(substream, &davinci_pcm_hardware);
+	ppcm = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
+			&pcm_hardware_playback : &pcm_hardware_capture;
+	allocate_sram(substream, params->sram_size, ppcm);
+	snd_soc_set_runtime_hwparams(substream, ppcm);
 	/* ensure that buffer size is a multiple of period size */
 	ret = snd_pcm_hw_constraint_integer(runtime,
 						SNDRV_PCM_HW_PARAM_PERIODS);
@@ -272,6 +669,11 @@ static int davinci_pcm_open(struct snd_pcm_substream *substream)
 
 	spin_lock_init(&prtd->lock);
 	prtd->params = params;
+	prtd->asp_channel = -1;
+	prtd->asp_link[0] = prtd->asp_link[1] = -1;
+	prtd->ram_channel = -1;
+	prtd->ram_link = -1;
+	prtd->ram_link2 = -1;
 
 	runtime->private_data = prtd;
 
@@ -289,10 +691,29 @@ static int davinci_pcm_close(struct snd_pcm_substream *substream)
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct davinci_runtime_data *prtd = runtime->private_data;
 
+	if (prtd->ram_channel >= 0)
+		edma_stop(prtd->ram_channel);
+	if (prtd->asp_channel >= 0)
+		edma_stop(prtd->asp_channel);
+	if (prtd->asp_link[0] >= 0)
 		edma_unlink(prtd->asp_link[0]);
+	if (prtd->asp_link[1] >= 0)
+		edma_unlink(prtd->asp_link[1]);
+	if (prtd->ram_link >= 0)
+		edma_unlink(prtd->ram_link);
 
+	if (prtd->asp_link[0] >= 0)
 		edma_free_slot(prtd->asp_link[0]);
+	if (prtd->asp_link[1] >= 0)
+		edma_free_slot(prtd->asp_link[1]);
+	if (prtd->asp_channel >= 0)
 		edma_free_channel(prtd->asp_channel);
+	if (prtd->ram_link >= 0)
+		edma_free_slot(prtd->ram_link);
+	if (prtd->ram_link2 >= 0)
+		edma_free_slot(prtd->ram_link2);
+	if (prtd->ram_channel >= 0)
+		edma_free_channel(prtd->ram_channel);
 
 	kfree(prtd);
 
@@ -334,11 +755,11 @@ static struct snd_pcm_ops davinci_pcm_ops = {
 	.mmap = 	davinci_pcm_mmap,
 };
 
-static int davinci_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
+static int davinci_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream,
+		size_t size)
 {
 	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
 	struct snd_dma_buffer *buf = &substream->dma_buffer;
-	size_t size = davinci_pcm_hardware.buffer_bytes_max;
 
 	buf->dev.type = SNDRV_DMA_TYPE_DEV;
 	buf->dev.dev = pcm->card->dev;
@@ -363,6 +784,7 @@ static void davinci_pcm_free(struct snd_pcm *pcm)
 	int stream;
 
 	for (stream = 0; stream < 2; stream++) {
+		struct snd_dma_buffer *iram_dma;
 		substream = pcm->streams[stream].substream;
 		if (!substream)
 			continue;
@@ -374,6 +796,11 @@ static void davinci_pcm_free(struct snd_pcm *pcm)
 		dma_free_writecombine(pcm->card->dev, buf->bytes,
 				      buf->area, buf->addr);
 		buf->area = NULL;
+		iram_dma = (struct snd_dma_buffer *)buf->private_data;
+		if (iram_dma) {
+			sram_free(iram_dma->area, iram_dma->bytes);
+			kfree(iram_dma);
+		}
 	}
 }
 
@@ -391,14 +818,16 @@ static int davinci_pcm_new(struct snd_card *card,
 
 	if (dai->playback.channels_min) {
 		ret = davinci_pcm_preallocate_dma_buffer(pcm,
-			SNDRV_PCM_STREAM_PLAYBACK);
+			SNDRV_PCM_STREAM_PLAYBACK,
+			pcm_hardware_playback.buffer_bytes_max);
 		if (ret)
 			return ret;
 	}
 
 	if (dai->capture.channels_min) {
 		ret = davinci_pcm_preallocate_dma_buffer(pcm,
-			SNDRV_PCM_STREAM_CAPTURE);
+			SNDRV_PCM_STREAM_CAPTURE,
+			pcm_hardware_capture.buffer_bytes_max);
 		if (ret)
 			return ret;
 	}

sound/soc/davinci/davinci-pcm.h

@@ -20,6 +20,7 @@ struct davinci_pcm_dma_params {
 	int channel;			/* sync dma channel ID */
 	unsigned short acnt;
 	dma_addr_t dma_addr;		/* device physical address for DMA */
+	unsigned sram_size;
 	enum dma_event_q eventq_no;	/* event queue number */
 	unsigned char data_type;	/* xfer data type */
 	unsigned char convert_mono_stereo;