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[0/2] STM32 DMA alternative REQ/ACK protocol support

Message ID 20210624093959.142265-1-amelie.delaunay@foss.st.com (mailing list archive)
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Series STM32 DMA alternative REQ/ACK protocol support | expand

Message

Amelie Delaunay June 24, 2021, 9:39 a.m. UTC 
Default REQ/ACK protocol consists in maintaining ACK signal up to the
removal of REQuest and the transfer completion.
In case of alternative REQ/ACK protocol, ACK de-assertion does not wait the
removal of the REQuest, but only the transfer completion.
Due to a possible DMA stream lock when transferring data to/from STM32
USART/UART, add support to select alternative REQ/ACK protocol.

Amelie Delaunay (2):
  dt-bindings: dma: add alternative REQ/ACK protocol selection in
    stm32-dma
  dmaengine: stm32-dma: add alternate REQ/ACK protocol management

 Documentation/devicetree/bindings/dma/st,stm32-dma.yaml | 7 +++++++
 drivers/dma/stm32-dma.c                                 | 8 ++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

Comments

Vinod Koul July 28, 2021, 7:09 a.m. UTC | #1 
On 24-06-21, 11:39, Amelie Delaunay wrote:
> Default REQ/ACK protocol consists in maintaining ACK signal up to the
> removal of REQuest and the transfer completion.
> In case of alternative REQ/ACK protocol, ACK de-assertion does not wait the
> removal of the REQuest, but only the transfer completion.
> Due to a possible DMA stream lock when transferring data to/from STM32
> USART/UART, add support to select alternative REQ/ACK protocol.

Applied, thanks