From 943d8d8bca431d6c93f17bf38f4b09c65e0a81d7 Mon Sep 17 00:00:00 2001 From: Tomoya MORINAGA Date: Wed, 1 Dec 2010 19:49:48 +0900 Subject: [PATCH] dma : EG20T PCH: Fix miss-setting DMA descriptor Currently, in case of using scatter/gather mode, head of data is not sent to destination. The cause is second descriptor address is set to NEXT. The NEXT must have head of descriptor address. This patch sets head of descriptor address to the NEXT. Acked-by: Yong Wang Signed-off-by: Tomoya MORINAGA [dan.j.williams@intel.com: fixed up usage of virt_to_phys()] Signed-off-by: Dan Williams --- drivers/dma/pch_dma.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/dma/pch_dma.c b/drivers/dma/pch_dma.c index 92b6790..c064c89 100644 --- a/drivers/dma/pch_dma.c +++ b/drivers/dma/pch_dma.c @@ -259,11 +259,6 @@ static void pdc_dostart(struct pch_dma_chan *pd_chan, struct pch_dma_desc* desc) return; } - channel_writel(pd_chan, DEV_ADDR, desc->regs.dev_addr); - channel_writel(pd_chan, MEM_ADDR, desc->regs.mem_addr); - channel_writel(pd_chan, SIZE, desc->regs.size); - channel_writel(pd_chan, NEXT, desc->regs.next); - dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> dev_addr: %x\n", pd_chan->chan.chan_id, desc->regs.dev_addr); dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> mem_addr: %x\n", @@ -273,10 +268,16 @@ static void pdc_dostart(struct pch_dma_chan *pd_chan, struct pch_dma_desc* desc) dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> next: %x\n", pd_chan->chan.chan_id, desc->regs.next); - if (list_empty(&desc->tx_list)) + if (list_empty(&desc->tx_list)) { + channel_writel(pd_chan, DEV_ADDR, desc->regs.dev_addr); + channel_writel(pd_chan, MEM_ADDR, desc->regs.mem_addr); + channel_writel(pd_chan, SIZE, desc->regs.size); + channel_writel(pd_chan, NEXT, desc->regs.next); pdc_set_mode(&pd_chan->chan, DMA_CTL0_ONESHOT); - else + } else { + channel_writel(pd_chan, NEXT, desc->txd.phys); pdc_set_mode(&pd_chan->chan, DMA_CTL0_SG); + } val = dma_readl(pd, CTL2); val |= 1 << (DMA_CTL2_START_SHIFT_BITS + pd_chan->chan.chan_id); -- 2.7.4