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authorSteven Miao <realmz6@gmail.com>2011-05-05 14:14:48 +0800
committerMike Frysinger <vapier@gentoo.org>2011-05-25 08:24:14 -0400
commitf9691bb9674b6822ace56370a08c6fc02addf6cb (patch)
tree40f9f39d38326c498ea5f3d63cd2c1e059b8bf21
parent7a7a430f7498cd55820232d8e3f144161138f91a (diff)
downloadblackbird-op-linux-f9691bb9674b6822ace56370a08c6fc02addf6cb.tar.gz
blackbird-op-linux-f9691bb9674b6822ace56370a08c6fc02addf6cb.zip
Blackfin: work around anomaly 05000480
Anomaly 05000480 on BF537 rev 0.0, 0.1, 0.2: Multiple Simultaneous Urgent DMA Requests May Cause DMA System Instability Suggested Workaround: Program the DMA Traffic Control Period to a non-zero value. This forces the DMA block to group accesses together rather than allow arbitration for each piece of data placed on the internal DMA bus. Signed-off-by: Steven Miao <realmz6@gmail.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
-rw-r--r--arch/blackfin/kernel/bfin_dma_5xx.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c
index 6ce8dce753c9..71dbaa4a48af 100644
--- a/arch/blackfin/kernel/bfin_dma_5xx.c
+++ b/arch/blackfin/kernel/bfin_dma_5xx.c
@@ -36,6 +36,11 @@ static int __init blackfin_dma_init(void)
printk(KERN_INFO "Blackfin DMA Controller\n");
+
+#if ANOMALY_05000480
+ bfin_write_DMAC_TC_PER(0x0111);
+#endif
+
for (i = 0; i < MAX_DMA_CHANNELS; i++) {
atomic_set(&dma_ch[i].chan_status, 0);
dma_ch[i].regs = dma_io_base_addr[i];
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