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author | Álvaro Fernández Rojas <noltari@gmail.com> | 2016-07-07 09:22:07 +0200 |
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committer | Álvaro Fernández Rojas <noltari@gmail.com> | 2016-07-09 16:29:18 +0200 |
commit | 20402106a376dcc4a766d3b0cee801ce29ba76d5 (patch) | |
tree | cfd93c19a6766663c4e8537ca8b8b82ad50478ee /target/linux/brcm2708/patches-4.4/0406-dmaengine-bcm2835-Fix-cyclic-DMA-period-splitting.patch | |
parent | f1765277bacbea47a45ed913ca8fa043e9f71393 (diff) | |
download | master-31e0f0ae-20402106a376dcc4a766d3b0cee801ce29ba76d5.tar.gz master-31e0f0ae-20402106a376dcc4a766d3b0cee801ce29ba76d5.tar.bz2 master-31e0f0ae-20402106a376dcc4a766d3b0cee801ce29ba76d5.zip |
brcm2708: update linux 4.4 patches to latest version
As usual these patches were extracted and rebased from the raspberry pi repo:
https://github.com/raspberrypi/linux/tree/rpi-4.4.y
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0406-dmaengine-bcm2835-Fix-cyclic-DMA-period-splitting.patch')
-rw-r--r-- | target/linux/brcm2708/patches-4.4/0406-dmaengine-bcm2835-Fix-cyclic-DMA-period-splitting.patch | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0406-dmaengine-bcm2835-Fix-cyclic-DMA-period-splitting.patch b/target/linux/brcm2708/patches-4.4/0406-dmaengine-bcm2835-Fix-cyclic-DMA-period-splitting.patch new file mode 100644 index 0000000000..56cceb04f3 --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0406-dmaengine-bcm2835-Fix-cyclic-DMA-period-splitting.patch @@ -0,0 +1,38 @@ +From 74d0d3161d711b51be692cf1750b6eb60719f782 Mon Sep 17 00:00:00 2001 +From: Matthias Reichl <hias@horus.com> +Date: Tue, 7 Jun 2016 19:37:10 +0200 +Subject: [PATCH 406/423] dmaengine: bcm2835: Fix cyclic DMA period splitting + +The code responsible for splitting periods into chunks that +can be handled by the DMA controller missed to update total_len, +the number of bytes processed in the current period, when there +are more chunks to follow. + +Therefore total_len was stuck at 0 and the code didn't work at all. +This resulted in a wrong control block layout and audio issues because +the cyclic DMA callback wasn't executing on period boundaries. + +Fix this by adding the missing total_len update. + +Signed-off-by: Matthias Reichl <hias@horus.com> +Signed-off-by: Martin Sperl <kernel@martin.sperl.org> +Tested-by: Clive Messer <clive.messer@digitaldreamtime.co.uk> +--- + drivers/dma/bcm2835-dma.c | 5 ++++- + 1 file changed, 4 insertions(+), 1 deletion(-) + +--- a/drivers/dma/bcm2835-dma.c ++++ b/drivers/dma/bcm2835-dma.c +@@ -252,8 +252,11 @@ static void bcm2835_dma_create_cb_set_le + */ + + /* have we filled in period_length yet? */ +- if (*total_len + control_block->length < period_len) ++ if (*total_len + control_block->length < period_len) { ++ /* update number of bytes in this period so far */ ++ *total_len += control_block->length; + return; ++ } + + /* calculate the length that remains to reach period_length */ + control_block->length = period_len - *total_len; |