dmaengine: xilinx_dma: Fix race condition in the driver for multiple descriptor scenario

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As per axi dmaengine spec the software must not move the tail pointer
to a location that has not been updated (next descriptor field of the
h/w descriptor should always point to a valid address).

When user submits multiple descriptors on the recv side, with the
current driver flow the last buffer descriptor next descriptor field
points to a invalid location, resulting the invalid data or errors from the
axidma dmaengine.

This patch fixes this issue by creating a buffer descritpor chain during
channel allocation itself and use those buffer descriptors for the
subsequent dma operations.

Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

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Kedareswara rao Appana 2017-12-07 10:51:04 +05:30 • committed by Vinod Koul

parent fe0503e193

commit 23059408b6

1 changed files with 84 additions and 51 deletions

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drivers/dma/xilinx/xilinx_dma.c

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