Subject: [PATCH v5 02/10] mtd: powernv_flash: Don't treat OPAL_SUCCESS as an error

From: Cyril Bur <[email-masked]>
Date: Fri, 3 Nov 2017 13:41:38 +1100

While this driver expects to interact asynchronously, OPAL is well
within its rights to return OPAL_SUCCESS to indicate that the operation
completed without the need for a callback. We shouldn't treat
OPAL_SUCCESS as an error rather we should wrap up and return promptly to
the caller.

Signed-off-by: Cyril Bur <[email-masked]>
Acked-by: Boris Brezillon <[email-masked]>
---
I'll note here that currently no OPAL exists that will return
OPAL_SUCCESS so there isn't the possibility of a bug today.
---
 drivers/mtd/devices/powernv_flash.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c
index f9ec38281ff2..ca3ca6adf71e 100644
--- a/drivers/mtd/devices/powernv_flash.c
+++ b/drivers/mtd/devices/powernv_flash.c
@@ -63,7 +63,6 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
 	if (token < 0) {
 		if (token != -ERESTARTSYS)
 			dev_err(dev, "Failed to get an async token\n");
-
 		return token;
 	}
 
@@ -83,21 +82,25 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
 		return -EIO;
 	}
 
+	if (rc == OPAL_SUCCESS)
+		goto out_success;
+
 	if (rc != OPAL_ASYNC_COMPLETION) {
 		dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n",
 				op, rc);
-		opal_async_release_token(token);
-		return -EIO;
+		rc = -EIO;
+		goto out;
 	}
 
 	rc = opal_async_wait_response(token, &msg);
-	opal_async_release_token(token);
 	if (rc) {
 		dev_err(dev, "opal async wait failed (rc %d)\n", rc);
-		return -EIO;
+		rc = -EIO;
+		goto out;
 	}
 
 	rc = opal_get_async_rc(msg);
+out_success:
 	if (rc == OPAL_SUCCESS) {
 		rc = 0;
 		if (retlen)
@@ -106,6 +109,8 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
 		rc = -EIO;
 	}
 
+out:
+	opal_async_release_token(token);
 	return rc;
 }
 
-- 
2.15.0