Re: [PATCH 1/1] cxl/mbox: Return success for CXL_MBOX_CMD_RC_BACKGROUND

From: Richard Cheng

Date: Tue Oct 20 2026 - 05:57:46 EST


On Tue, Oct 20, 2026 at 05:03:52PM +0800, Li Ming wrote:
> In CXL subsystem, each mbox command hw return code is mapped to a
> corresponding errno value. Currently, CXL_MBOX_CMD_RC_BACKGROUND is
> mapped to -ENXIO.
>
> However, a BACKGROUND hw return code indicates that the command has been
> accepted by the device and continues execution asynchronously. It does
> not indicate a command failure.
>

Hi Li,

Can we have the spec section written here ?
Btw I wonder how you trigger the error ?

Best regards,
Richard Cheng.

> Return 0 instead of -ENXIO for CXL_MBOX_CMD_RC_BACKGROUND so that
> callers do not treat a successfully started background operation as an
> error.
>
> Fixes: 92fcc1abab09 ("cxl/mbox: Improve handling of mbox_cmd hw return codes")
> Signed-off-by: Li Ming <ming.li@xxxxxxxxxxxx>
> ---
> drivers/cxl/cxlmem.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index c401e3a1af06..cc71d7a84cdc 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -160,7 +160,7 @@ static inline struct cxl_ep *cxl_ep_load(struct cxl_port *port,
> */
> #define CMD_CMD_RC_TABLE \
> C(SUCCESS, 0, NULL), \
> - C(BACKGROUND, -ENXIO, "background cmd started successfully"), \
> + C(BACKGROUND, 0, "background cmd started successfully"), \
> C(INPUT, -ENXIO, "cmd input was invalid"), \
> C(UNSUPPORTED, -ENXIO, "cmd is not supported"), \
> C(INTERNAL, -ENXIO, "internal device error"), \
> --
> 2.43.0
>