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authorFelix Fietkau <nbd@openwrt.org>2016-01-17 10:42:23 +0000
committerFelix Fietkau <nbd@openwrt.org>2016-01-17 10:42:23 +0000
commit4224b52c3acc7203e7c2535d6806f30432dae5e3 (patch)
tree7a847d3e84dfc3608555587c3b9958474fc17d72 /target/linux/brcm2708/patches-4.4/0024-bcm2835-dma-Limit-cyclic-transfers-on-lite-channels-.patch
parentcad399c87b7739c4b8eeb4119706860818f7d84f (diff)
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brcm2708: add linux 4.4 support
- random-bcm2708 and spi-bcm2708 have been removed. - sound-soc-bcm2708-i2s has been upstreamed as sound-soc-bcm2835-i2s. Let's keep linux 4.1 for a while, since linux 4.4 appears to have some issues with multicast traffic on RPi ethernet: https://gist.github.com/Noltari/5b1cfdecce5ed4bc08fd Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> SVN-Revision: 48266
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0024-bcm2835-dma-Limit-cyclic-transfers-on-lite-channels-.patch')
-rw-r--r--target/linux/brcm2708/patches-4.4/0024-bcm2835-dma-Limit-cyclic-transfers-on-lite-channels-.patch37
1 files changed, 37 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0024-bcm2835-dma-Limit-cyclic-transfers-on-lite-channels-.patch b/target/linux/brcm2708/patches-4.4/0024-bcm2835-dma-Limit-cyclic-transfers-on-lite-channels-.patch
new file mode 100644
index 0000000000..4461fec7a9
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.4/0024-bcm2835-dma-Limit-cyclic-transfers-on-lite-channels-.patch
@@ -0,0 +1,37 @@
+From c7e464c38d38ad59899c94dfad6c3455c18f7d76 Mon Sep 17 00:00:00 2001
+From: Matthias Reichl <hias@horus.com>
+Date: Sun, 11 Oct 2015 12:28:30 +0200
+Subject: [PATCH 024/127] bcm2835-dma: Limit cyclic transfers on lite channels
+ to 32k
+
+Transfers larger than 32k cause repeated clicking with I2S soundcards.
+The exact reason is yet unknown, so limit to 32k as bcm2708-dmaengine
+did as an intermediate fix.
+---
+ drivers/dma/bcm2835-dma.c | 8 +++++++-
+ 1 file changed, 7 insertions(+), 1 deletion(-)
+
+--- a/drivers/dma/bcm2835-dma.c
++++ b/drivers/dma/bcm2835-dma.c
+@@ -144,6 +144,12 @@ struct bcm2835_desc {
+ */
+ #define MAX_LITE_TRANSFER (SZ_64K - 4)
+
++/*
++ * Transfers larger than 32k cause issues with the bcm2708-i2s driver,
++ * so limit transfer size to 32k as bcm2708-dmaengine did.
++ */
++#define MAX_CYCLIC_LITE_TRANSFER SZ_32K
++
+ static inline struct bcm2835_dmadev *to_bcm2835_dma_dev(struct dma_device *d)
+ {
+ return container_of(d, struct bcm2835_dmadev, ddev);
+@@ -412,7 +418,7 @@ static struct dma_async_tx_descriptor *b
+ d->c = c;
+ d->dir = direction;
+ if (c->ch >= 8) /* LITE channel */
+- max_size = MAX_LITE_TRANSFER;
++ max_size = MAX_CYCLIC_LITE_TRANSFER;
+ else
+ max_size = MAX_NORMAL_TRANSFER;
+ period_len = min(period_len, max_size);