On 13/02/2023 02:50, ChiaWei Wang wrote: >> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> >> Sent: Friday, February 10, 2023 5:14 PM >> >> On 10/02/2023 08:26, Chia-Wei Wang wrote: >>> This driver provides DMA support for AST26xx UART and VUART devices. >>> It is useful to offload CPU overhead while using UART/VUART for binary >>> file transfer. >>> >>> Signed-off-by: Chia-Wei Wang <chiawei_wang@xxxxxxxxxxxxxx> >>> --- >>> drivers/soc/aspeed/Kconfig | 9 + >>> drivers/soc/aspeed/Makefile | 1 + >>> drivers/soc/aspeed/aspeed-udma.c | 447 >> +++++++++++++++++++++++++ >>> include/linux/soc/aspeed/aspeed-udma.h | 34 ++ >> >> NAK. >> >> DMA drivers do not go to soc, but to dma subsystem. > > The UDMA is dedicated only to UART use and is not fully fit to the DMAEngine subsystem. > For example, the suspend/resume operations of common DMA engine are not supported. > After observing certain existing DMA implementation in other soc folders, we put UDMA in the soc/aspeed as well. > If it is not appropriate, should we integrate UDMA into the UART driver or try to make UDMA DMAEngine based? You did not Cc dma folks, so how would I know... Maybe soc is right place if the DMA driver is not suitable for other consumers than UART. Maybe not. Best regards, Krzysztof