Re: [PATCH 0/3] dmaengine: Use non-atomic bit ops where safe

From: Frank Li

Date: Thu Sep 03 2026 - 15:40:06 EST


On Thu, Sep 03, 2026 at 10:16:11PM +0800, Peng Fan (OSS) wrote:
> dma_cap_set()/dma_cap_clear() and imx-sdma event_mask setup use atomic
> set_bit()/clear_bit() in contexts where no concurrent access is
> possible:
>
> - dma_cap_set()/dma_cap_clear() are called exclusively during driver
> probe, before dma_async_device_register() makes the device visible.
> - imx-sdma event_mask[] is zeroed and configured during channel setup
> while the channel is disabled.
>
> Switch both to non-atomic __set_bit()/__clear_bit() equivalents.

Any benefit to switch?

Frank

>
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> ---
> Peng Fan (3):
> dmaengine: Use non-atomic bit ops for cap_mask manipulation
> dmaengine: imx-sdma: Use non-atomic __set_bit() for event_mask setup
> dmaengine: imx-sdma: Use __assign_bit() for ownership configuration
>
> drivers/dma/imx-sdma.c | 21 +++++----------------
> include/linux/dmaengine.h | 4 ++--
> 2 files changed, 7 insertions(+), 18 deletions(-)
> ---
> base-commit: 89c07d98716a13454ec3fd9f97689e812cc71bd4
> change-id: 20260903-dma-mask-ddf64d770f7d
>
> Best regards,
> --
> Peng Fan <peng.fan@xxxxxxx>
>