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authorGeorge Cherian <george.cherian@ti.com>2014-02-27 06:14:40 +0100
committerVinod Koul <vinod.koul@intel.com>2014-03-11 11:52:43 +0100
commit975faaeb9985af9774007277fdb36b3dc897f4c3 (patch)
treeb9cdf451b48f25ad3752820463d0dc29f862b625 /drivers/dma
parentusb: musb: musb_cppi41: Dont reprogram DMA if tear down is initiated (diff)
downloadlinux-975faaeb9985af9774007277fdb36b3dc897f4c3.tar.xz
linux-975faaeb9985af9774007277fdb36b3dc897f4c3.zip
dma: cppi41: start tear down only if channel is busy
Start the channel tear down only if the channel is busy, else just bail out. In some cases its seen that by the time the tear down is initiated the cppi completes the DMA, especially in ISOCH transfers. Signed-off-by: George Cherian <george.cherian@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/cppi41.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/dma/cppi41.c b/drivers/dma/cppi41.c
index c18aebf7d5aa..d028f36ae655 100644
--- a/drivers/dma/cppi41.c
+++ b/drivers/dma/cppi41.c
@@ -620,12 +620,15 @@ static int cppi41_stop_chan(struct dma_chan *chan)
u32 desc_phys;
int ret;
+ desc_phys = lower_32_bits(c->desc_phys);
+ desc_num = (desc_phys - cdd->descs_phys) / sizeof(struct cppi41_desc);
+ if (!cdd->chan_busy[desc_num])
+ return 0;
+
ret = cppi41_tear_down_chan(c);
if (ret)
return ret;
- desc_phys = lower_32_bits(c->desc_phys);
- desc_num = (desc_phys - cdd->descs_phys) / sizeof(struct cppi41_desc);
WARN_ON(!cdd->chan_busy[desc_num]);
cdd->chan_busy[desc_num] = NULL;