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 <youg.y.wang@intel.com>
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
[dan.j.williams@intel.com: fixed up usage of virt_to_phys()]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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 @@
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 @@
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);