[PATCH v2 1/2] cxl/mbox: Return success for CXL_MBOX_CMD_RC_BACKGROUND

[PATCH v2 1/2] cxl/mbox: Return success for CXL_MBOX_CMD_RC_BACKGROUND

[Li Ming]

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, per Table-8-208 in CXL r4.0 section 8.2.9.4.5.1, 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.

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@zohomail.com>
---
v2:
- Add a reference to the relevant spec section in the commit log.
---
 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

[PATCH v2 2/2] cxl/mbox: Use mapped errno to determine command status

[Li Ming]

cxl_mbox_cmd_rctable already maps all mailbox command return codes to
errno values. Use the returned errno directly instead of checking
mailbox return codes separately to determine whether a command succeeded
or failed.

Signed-off-by: Li Ming <ming.li@zohomail.com>
---
v2:
- New patch.
---
 drivers/cxl/core/mbox.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 55828a836c01..bd91b03c4d21 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -270,9 +270,9 @@ int cxl_internal_send_cmd(struct cxl_mailbox *cxl_mbox,
 	if (rc)
 		return rc;
 
-	if (mbox_cmd->return_code != CXL_MBOX_CMD_RC_SUCCESS &&
-	    mbox_cmd->return_code != CXL_MBOX_CMD_RC_BACKGROUND)
-		return cxl_mbox_cmd_rc2errno(mbox_cmd);
+	rc = cxl_mbox_cmd_rc2errno(mbox_cmd);
+	if (rc)
+		return rc;
 
 	if (!out_size)
 		return 0;
-- 
2.43.0