mmc: core: use enum mmc_blk_status properly

There were several instances of code using the
enum mmc_blk_status by arbitrarily converting it to an int and
throwing it around to different functions. This makes the code
hard to understand to may give rise to strange errors.

Especially the function prototype mmc_start_req() had to be
modified to take a pointer to an enum mmc_blk_status and the
function pointer .err_check() inside struct mmc_async_req
needed to return an enum mmc_blk_status.

In every case: instead of assigning the block layer error code
to an int, use the enum, also change the signature of all
functions actually passing this enum to use the enum.

To make it possible to use the enum everywhere applicable, move
it to <linux/mmc/core.h> so that all code actually using it can
also see it.

An interesting case was encountered in the MMC test code which
did not return a enum mmc_blk_status at all in the .err_check
function supposed to check whether asynchronous requests worked
or not: instead it returned a normal -ERROR or even the test
frameworks internal error codes.

The test code would also pass on enum mmc_blk_status codes as
error codes inside the test code instead of converting them
to the local RESULT_* codes.

I have tried to fix all instances properly and run some tests
on the result.

Cc: Chunyan Zhang <zhang.chunyan@linaro.org>
Cc: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 18 insertions, 17 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 2ad729138bee..50bb9a16380d 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -497,13 +497,13 @@ static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
  *
  * Returns enum mmc_blk_status after checking errors.
  */
-static int mmc_wait_for_data_req_done(struct mmc_host *host,
+static enum mmc_blk_status mmc_wait_for_data_req_done(struct mmc_host *host,
 				      struct mmc_request *mrq,
 				      struct mmc_async_req *next_req)
 {
 	struct mmc_command *cmd;
 	struct mmc_context_info *context_info = &host->context_info;
-	int err;
+	enum mmc_blk_status status;
 	unsigned long flags;
 
 	while (1) {
@@ -520,9 +520,9 @@ static int mmc_wait_for_data_req_done(struct mmc_host *host,
 
 			if (!cmd->error || !cmd->retries ||
 			    mmc_card_removed(host->card)) {
-				err = host->areq->err_check(host->card,
-							    host->areq);
-				break; /* return err */
+				status = host->areq->err_check(host->card,
+							       host->areq);
+				break; /* return status */
 			} else {
 				mmc_retune_recheck(host);
 				pr_info("%s: req failed (CMD%u): %d, retrying...\n",
@@ -540,7 +540,7 @@ static int mmc_wait_for_data_req_done(struct mmc_host *host,
 		}
 	}
 	mmc_retune_release(host);
-	return err;
+	return status;
 }
 
 void mmc_wait_for_req_done(struct mmc_host *host, struct mmc_request *mrq)
@@ -658,9 +658,10 @@ static void mmc_post_req(struct mmc_host *host, struct mmc_request *mrq,
  *	is returned without waiting. NULL is not an error condition.
  */
 struct mmc_async_req *mmc_start_req(struct mmc_host *host,
-				    struct mmc_async_req *areq, int *error)
+				    struct mmc_async_req *areq,
+				    enum mmc_blk_status *ret_stat)
 {
-	int err = 0;
+	enum mmc_blk_status status = MMC_BLK_SUCCESS;
 	int start_err = 0;
 	struct mmc_async_req *data = host->areq;
 
@@ -669,10 +670,10 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
 		mmc_pre_req(host, areq->mrq, !host->areq);
 
 	if (host->areq) {
-		err = mmc_wait_for_data_req_done(host, host->areq->mrq,	areq);
-		if (err == MMC_BLK_NEW_REQUEST) {
-			if (error)
-				*error = err;
+		status = mmc_wait_for_data_req_done(host, host->areq->mrq, areq);
+		if (status == MMC_BLK_NEW_REQUEST) {
+			if (ret_stat)
+				*ret_stat = status;
 			/*
 			 * The previous request was not completed,
 			 * nothing to return
@@ -699,23 +700,23 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
 		}
 	}
 
-	if (!err && areq)
+	if (status == MMC_BLK_SUCCESS && areq)
 		start_err = __mmc_start_data_req(host, areq->mrq);
 
 	if (host->areq)
 		mmc_post_req(host, host->areq->mrq, 0);
 
 	 /* Cancel a prepared request if it was not started. */
-	if ((err || start_err) && areq)
+	if ((status != MMC_BLK_SUCCESS || start_err) && areq)
 		mmc_post_req(host, areq->mrq, -EINVAL);
 
-	if (err)
+	if (status != MMC_BLK_SUCCESS)
 		host->areq = NULL;
 	else
 		host->areq = areq;
 
-	if (error)
-		*error = err;
+	if (ret_stat)
+		*ret_stat = status;
 	return data;
 }
 EXPORT_SYMBOL(mmc_start_req);