dmaengine: at_xdmac: double FIFO flush needed to compute residue

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commit 9295c41d77 upstream.

Due to the way CUBC register is updated, a double flush is needed to
compute an accurate residue. First flush aim is to get data from the DMA
FIFO and second one ensures that we won't report data which are not in
memory.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Fixes: e1f7c9eee7 ("dmaengine: at_xdmac: creation of the atmel
eXtended DMA Controller driver")
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Ludovic Desroches 2016-05-12 16:54:10 +02:00 • committed by Greg Kroah-Hartman

parent 5ce7333f41

commit 6b373d53e8

1 changed files with 23 additions and 1 deletions

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drivers/dma/at_xdmac.c

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