drivers: dma: siwx91x: Fix DMA_ADDR_ADJ_NO_CHANGE w/ memory destination
GPDMA does not support DMA_ADDR_ADJ_NO_CHANGE with a memory buffer. This
feature is required fro the SPI driver. Hopefully, SPI driver is the only
user of this feature.
Therefore, this commit introduces a hack for SPI. When the user want to
ignore the Rx data (= when he pass a NULL pointer for the Rx buffer),
rather than overwriting the destination in a loop, we just disable the rx
DMA.
This introduce a limitation: since Rx DMA stop early, any following Rx
request will start earlier than expected. Therefore, this patch breaks
cases with interleaved Rx buffers. In other words, the NULL buffer must be
the last one.
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
2 files changed
