[PATCH] firmware: arm_scmi: fix SMCCC_RET_NOT_SUPPORTED management

[Etienne Carriere]

Fix management of argument a0 output value of arm_smccc_1_1_invoke() that
should consider only SMCCC_RET_NOT_SUPPORTED as reporting an unsupported
function ID as correctly stated in the inline comment.

Signed-off-by: Etienne Carriere <etienne.carriere@xxxxxxxxxx>
---
 drivers/firmware/arm_scmi/smc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
index 49bc4b0e8428..637ad439545f 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -115,7 +115,7 @@ static int smc_send_message(struct scmi_chan_info *cinfo,
 	mutex_unlock(&scmi_info->shmem_lock);
 
 	/* Only SMCCC_RET_NOT_SUPPORTED is valid error code */
-	if (res.a0)
+	if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
 		return -EOPNOTSUPP;
 	return 0;
 }
-- 
2.17.1