From 41245ac5952e5b05e6fbb7c188eae0947f640189 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Wed, 4 Feb 2009 16:49:45 +0800 Subject: [PATCH] Blackfin arch: fix bug - Dmacopy failed in BF537-STAMP Dmacopy failed in BF537-STAMP when copy from SRAM to SDRAM and kernel will reboot automatically. Fixing by doing a SSYNC before mucking with DMA registers Signed-off-by: Mike Frysinger Signed-off-by: Bryan Wu --- arch/blackfin/kernel/bfin_dma_5xx.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c index 07e02c0d1c0..8531693fb48 100644 --- a/arch/blackfin/kernel/bfin_dma_5xx.c +++ b/arch/blackfin/kernel/bfin_dma_5xx.c @@ -249,6 +249,13 @@ static void __dma_memcpy(u32 daddr, s16 dmod, u32 saddr, s16 smod, size_t cnt, u spin_lock_irqsave(&mdma_lock, flags); + /* Force a sync in case a previous config reset on this channel + * occurred. This is needed so subsequent writes to DMA registers + * are not spuriously lost/corrupted. Do it under irq lock and + * without the anomaly version (because we are atomic already). + */ + __builtin_bfin_ssync(); + if (bfin_read_MDMA_S0_CONFIG()) while (!(bfin_read_MDMA_D0_IRQ_STATUS() & DMA_DONE)) continue; -- 2.20.1