[PATCH v5 7/7] cxl/fwctl: Propagate feature RPC delivery errors

[Richard Cheng <icheng@nvidia.com>]

FWCTL_RPC requires delivery failures to be returned as ioctl errors,
while device errors are reported in the output. Get and Set Feature
instead converted all failures into normal responses, sometimes with a
SUCCESS device status.

Initialize the return code to SUCCESS. When the helper fails without a
device error code, return its errno. Continue reporting actual device
errors through rpc_out->retval.

Fixes: 5908f3ed6dc2 ("cxl: Add support to handle user feature commands for get feature")
Fixes: eb5dfcb9e36d ("cxl: Add support to handle user feature commands for set feature")
Signed-off-by: Richard Cheng <icheng@nvidia.com>
---
 drivers/cxl/core/features.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
index 8d44ce829497..30e00faaf3a9 100644
--- a/drivers/cxl/core/features.c
+++ b/drivers/cxl/core/features.c
@@ -232,7 +232,7 @@ ssize_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
 	int rc;
 
 	if (return_code)
-		*return_code = CXL_MBOX_CMD_RC_INPUT;
+		*return_code = CXL_MBOX_CMD_RC_SUCCESS;
 
 	if (!feat_out || !feat_out_size)
 		return -EINVAL;
@@ -289,7 +289,7 @@ int cxl_set_feature(struct cxl_mailbox *cxl_mbox,
 	size_t hdr_size;
 
 	if (return_code)
-		*return_code = CXL_MBOX_CMD_RC_INPUT;
+		*return_code = CXL_MBOX_CMD_RC_SUCCESS;
 
 	if (feat_data_size > U16_MAX - offset)
 		return -EINVAL;
@@ -492,6 +492,9 @@ static void *cxlctl_get_feature(struct cxl_features_state *cxlfs,
 	data_size = cxl_get_feature(cxl_mbox, &feat_in->uuid,
 				    feat_in->selection, rpc_out->payload,
 				    count, offset, &return_code);
+	if (data_size < 0 &&
+	    return_code == CXL_MBOX_CMD_RC_SUCCESS)
+		return ERR_PTR(data_size);
 	*out_len = sizeof(struct fwctl_rpc_cxl_out);
 	if (data_size <= 0) {
 		rpc_out->size = 0;
@@ -544,6 +547,8 @@ static void *cxlctl_set_feature(struct cxl_features_state *cxlfs,
 	rc = cxl_set_feature(cxl_mbox, &feat_in->uuid,
 			     feat_in->version, feat_in->feat_data,
 			     data_size, flags, offset, &return_code);
+	if (rc && return_code == CXL_MBOX_CMD_RC_SUCCESS)
+		return ERR_PTR(rc);
 	*out_len = sizeof(*rpc_out);
 	if (rc) {
 		rpc_out->retval = return_code;
-- 
2.43.0