[PATCH v4 0/2] dma: pl330: improve status checking

From: Robert Baldyga
Date: Wed Feb 11 2015 - 07:23:49 EST


Hello,

This series allows to check DMA transfer residue (number of bytes left
to send/receive) by modifying pl330_tx_status() function, when struct
dma_tx_state is filled with needed data. It also introduces DMA_PAUSE
feature, which allows to halt DMA transfer before termination and read
residue without risk of data loss.

This features are needed for proper implementation of DMA transfers,
particulary for serial drivers when transfer sizes are unknown and
requests on DMA channels are terminated before transfer completion
very ofter (it's becouse we terminate then in timeout interrupt to
avoid latency which is usually undesirable).

Best regards,
Robert Baldyga

Changelog:

v4:
- fixed comments from Vinod Koul
- rebased to latest linux-next

v3: https://lkml.org/lkml/2014/12/10/156
- remove double pm_runtime_put()

v2: https://lkml.org/lkml/2014/12/5/94
- add pm_runtime support
- make it working for multi-segment transfers
- some cleanups

v1: https://lkml.org/lkml/2014/11/25/554

Robert Baldyga (2):
dma: pl330: improve pl330_tx_status() function
dma: pl330: add DMA_PAUSE feature

drivers/dma/pl330.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 100 insertions(+), 2 deletions(-)

--
1.9.1

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