diff options
Diffstat (limited to 'main/linux-rpi/rpi-dma-i2s-fix.patch')
| -rw-r--r-- | main/linux-rpi/rpi-dma-i2s-fix.patch | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/main/linux-rpi/rpi-dma-i2s-fix.patch b/main/linux-rpi/rpi-dma-i2s-fix.patch new file mode 100644 index 0000000000..82fa6dcf7c --- /dev/null +++ b/main/linux-rpi/rpi-dma-i2s-fix.patch @@ -0,0 +1,66 @@ +From 8a2e9aec63f46deceacd0a92a66835a07fb18a31 Mon Sep 17 00:00:00 2001 +From: Matthias Reichl <hias@horus.com> +Date: Sun, 8 Nov 2015 16:58:57 +0100 +Subject: [PATCH] bcm2708-dmaengine: fix calculation of cyclic DMA frames + +The calculation of the number of required frames was wrong which +could lead to the last frame being longer than the requested period +length and even the maximum supported transfer size. + +eg when requesting a 88208 bytes buffer with a period len of 22052 +(the defaults when playing a 44.1kHz stereo 16bit file with aplay) +the code would allocate 3 frames, two with 22052 bytes and the +last one with 44104 bytes instead of the expected 4 frames with +22052 bytes each. + +Signed-off-by: Matthias Reichl <hias@horus.com> +--- + drivers/dma/bcm2708-dmaengine.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/drivers/dma/bcm2708-dmaengine.c b/drivers/dma/bcm2708-dmaengine.c +index 85ce18b..91eac60 100644 +--- a/drivers/dma/bcm2708-dmaengine.c ++++ b/drivers/dma/bcm2708-dmaengine.c +@@ -710,7 +710,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic( + max_size = MAX_NORMAL_TRANSFER; + period_len = min(period_len, max_size); + +- d->frames = (buf_len-1) / period_len + 1; ++ d->frames = DIV_ROUND_UP(buf_len, period_len); + + /* Allocate memory for control blocks */ + d->control_block_size = d->frames * sizeof(struct bcm2835_dma_cb); +-- +2.6.3 + + +From 8e469d0e00fa0f337e0e5ccdb504ce0ecf6ea6d6 Mon Sep 17 00:00:00 2001 +From: Matthias Reichl <hias@horus.com> +Date: Sun, 8 Nov 2015 17:00:45 +0100 +Subject: [PATCH] bcm2708-i2s: match period_bytes_max to DMA controller limit + +bcm2708-dmaengine supports a maximum transfer length of 32k bytes on +the lite channels. period_bytes_max should reflect this limit. + +Signed-off-by: Matthias Reichl <hias@horus.com> +--- + sound/soc/bcm/bcm2708-i2s.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/sound/soc/bcm/bcm2708-i2s.c b/sound/soc/bcm/bcm2708-i2s.c +index 5e93cd6..b65d785 100644 +--- a/sound/soc/bcm/bcm2708-i2s.c ++++ b/sound/soc/bcm/bcm2708-i2s.c +@@ -881,7 +881,7 @@ static struct snd_pcm_hardware bcm2708_pcm_hardware = { + SNDRV_PCM_FMTBIT_S24_LE | + SNDRV_PCM_FMTBIT_S32_LE, + .period_bytes_min = 32, +- .period_bytes_max = 64 * PAGE_SIZE, ++ .period_bytes_max = SZ_32K, + .periods_min = 2, + .periods_max = 255, + .buffer_bytes_max = 128 * PAGE_SIZE, +-- +2.6.3 + |