lkml.org 
[lkml]   [2011]   [Mar]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] dmaengine/dw_dmac fix: dwc_scan_descriptors must compare first desc address also with llp
Date
dwc_scan_descriptors scans all descriptors from active_list in case transfer is
not completed. It compares first_desc->lli.llp, and then all childrens of its
tx_list. But it doesn't compare its own address, i.e. first_desc->txd.phys, as
this is what we have initially programmed into the controller register. So this
causes dma to stop and finish a transfer, which was never started. And thus
fail.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
---
drivers/dma/dw_dmac.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index b95e6d3..1bd4803 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -304,6 +304,11 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);

list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
+ /* check first descriptors addr */
+ if (desc->txd.phys == llp)
+ return;
+
+ /* check first descriptors llp */
if (desc->lli.llp == llp)
/* This one is currently in progress */
return;
--
1.7.2.2


\
 
 \ /
  Last update: 2011-03-24 07:05    [from the cache]
©2003-2011 Jasper Spaans