[target/xburst] level up target xburst to linux kernel version 3.2.1

[openwrt.git] / target / linux / xburst / patches-3.2 / 0016-ASoC-JZ4740-Support-buffer-size-that-is-not-a-multip.patch

diff --git a/target/linux/xburst/patches-3.2/0016-ASoC-JZ4740-Support-buffer-size-that-is-not-a-multip.patch b/target/linux/xburst/patches-3.2/0016-ASoC-JZ4740-Support-buffer-size-that-is-not-a-multip.patch
new file mode 100644 (file)
index 0000000..5c300a2
--- /dev/null
+++ b/target/linux/xburst/patches-3.2/0016-ASoC-JZ4740-Support-buffer-size-that-is-not-a-multip.patch
@@ -0,0 +1,94 @@
+From 8a5087fe59e31efb8641e704058328997c3c8ff1 Mon Sep 17 00:00:00 2001
+From: Maarten ter Huurne <maarten@treewalker.org>
+Date: Wed, 10 Aug 2011 00:25:11 +0200
+Subject: [PATCH 16/21] ASoC: JZ4740: Support buffer size that is not a
+ multiple of period size.
+
+This fixes glitches triggered by libao, which sets time-based intervals
+instead of byte-based intervals like SDL does.
+
+Thanks to Paul Cercueil for figuring out that the buffer size was causing
+the glitches and to Lars Clausen for helping me write the fix.
+---
+ sound/soc/jz4740/jz4740-pcm.c |   21 ++++++++++++++++++---
+ 1 files changed, 18 insertions(+), 3 deletions(-)
+
+diff --git a/sound/soc/jz4740/jz4740-pcm.c b/sound/soc/jz4740/jz4740-pcm.c
+index d1989cd..1f9a005 100644
+--- a/sound/soc/jz4740/jz4740-pcm.c
++++ b/sound/soc/jz4740/jz4740-pcm.c
+@@ -31,6 +31,7 @@
+ 
+ struct jz4740_runtime_data {
+       unsigned long dma_period;
++      unsigned long dma_period_left;
+       dma_addr_t dma_start;
+       dma_addr_t dma_pos;
+       dma_addr_t dma_end;
+@@ -67,10 +68,13 @@ static void jz4740_pcm_start_transfer(struct jz4740_runtime_data *prtd,
+       if (prtd->dma_pos == prtd->dma_end)
+               prtd->dma_pos = prtd->dma_start;
+ 
+-      if (prtd->dma_pos + prtd->dma_period > prtd->dma_end)
++      if (prtd->dma_period_left == 0)
++              prtd->dma_period_left = prtd->dma_period;
++
++      if (prtd->dma_pos + prtd->dma_period_left > prtd->dma_end)
+               count = prtd->dma_end - prtd->dma_pos;
+       else
+-              count = prtd->dma_period;
++              count = prtd->dma_period_left;
+ 
+       jz4740_dma_disable(prtd->dma);
+ 
+@@ -85,6 +89,7 @@ static void jz4740_pcm_start_transfer(struct jz4740_runtime_data *prtd,
+       jz4740_dma_set_transfer_count(prtd->dma, count);
+ 
+       prtd->dma_pos += count;
++      prtd->dma_period_left -= count;
+ 
+       jz4740_dma_enable(prtd->dma);
+ }
+@@ -96,7 +101,8 @@ static void jz4740_pcm_dma_transfer_done(struct jz4740_dma_chan *dma, int err,
+       struct snd_pcm_runtime *runtime = substream->runtime;
+       struct jz4740_runtime_data *prtd = runtime->private_data;
+ 
+-      snd_pcm_period_elapsed(substream);
++      if (prtd->dma_period_left == 0)
++              snd_pcm_period_elapsed(substream);
+ 
+       jz4740_pcm_start_transfer(prtd, substream);
+ }
+@@ -133,6 +139,7 @@ static int jz4740_pcm_hw_params(struct snd_pcm_substream *substream,
+       runtime->dma_bytes = params_buffer_bytes(params);
+ 
+       prtd->dma_period = params_period_bytes(params);
++      prtd->dma_period_left = 0;
+       prtd->dma_start = runtime->dma_addr;
+       prtd->dma_pos = prtd->dma_start;
+       prtd->dma_end = prtd->dma_start + runtime->dma_bytes;
+@@ -160,6 +167,7 @@ static int jz4740_pcm_prepare(struct snd_pcm_substream *substream)
+       if (!prtd->dma)
+               return -EBUSY;
+ 
++      prtd->dma_period_left = 0;
+       prtd->dma_pos = prtd->dma_start;
+ 
+       return 0;
+@@ -219,6 +227,13 @@ static int jz4740_pcm_open(struct snd_pcm_substream *substream)
+       if (prtd == NULL)
+               return -ENOMEM;
+ 
++      /* Force period and buffer size to be a multiple of the DMA transfer
++       * size, which is 16 bytes. */
++      snd_pcm_hw_constraint_step(runtime, 0,
++                                 SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 16);
++      snd_pcm_hw_constraint_step(runtime, 0,
++                                 SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 16);
++
+       snd_soc_set_runtime_hwparams(substream, &jz4740_pcm_hardware);
+ 
+       runtime->private_data = prtd;
+-- 
+1.7.5.4
+