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>

2 files changed, 41 insertions, 16 deletions

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 62e38bc30618..49c2a2be7bb8 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1320,8 +1320,8 @@ static inline void mmc_apply_rel_rw(struct mmc_blk_request *brq,
 	 R1_CC_ERROR |		/* Card controller error */		\
 	 R1_ERROR)		/* General/unknown error */
 
-static int mmc_blk_err_check(struct mmc_card *card,
-			     struct mmc_async_req *areq)
+static enum mmc_blk_status mmc_blk_err_check(struct mmc_card *card,
+					     struct mmc_async_req *areq)
 {
 	struct mmc_queue_req *mq_mrq = container_of(areq, struct mmc_queue_req,
 						    mmc_active);
@@ -1433,14 +1433,15 @@ static int mmc_blk_err_check(struct mmc_card *card,
 	return MMC_BLK_SUCCESS;
 }
 
-static int mmc_blk_packed_err_check(struct mmc_card *card,
-				    struct mmc_async_req *areq)
+static enum mmc_blk_status mmc_blk_packed_err_check(struct mmc_card *card,
+						    struct mmc_async_req *areq)
 {
 	struct mmc_queue_req *mq_rq = container_of(areq, struct mmc_queue_req,
 			mmc_active);
 	struct request *req = mq_rq->req;
 	struct mmc_packed *packed = mq_rq->packed;
-	int err, check, status;
+	enum mmc_blk_status status, check;
+	int err;
 	u8 *ext_csd;
 
 	packed->retries--;
@@ -1995,7 +1996,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 			areq = &mq->mqrq_cur->mmc_active;
 		} else
 			areq = NULL;
-		areq = mmc_start_req(card->host, areq, (int *) &status);
+		areq = mmc_start_req(card->host, areq, &status);
 		if (!areq) {
 			if (status == MMC_BLK_NEW_REQUEST)
 				mq->flags |= MMC_QUEUE_NEW_REQUEST;
diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
index 3678220964fe..f61c812995ae 100644
--- a/drivers/mmc/card/mmc_test.c
+++ b/drivers/mmc/card/mmc_test.c
@@ -736,15 +736,28 @@ static int mmc_test_check_result(struct mmc_test_card *test,
 	return ret;
 }
 
-static int mmc_test_check_result_async(struct mmc_card *card,
+static enum mmc_blk_status mmc_test_check_result_async(struct mmc_card *card,
 				       struct mmc_async_req *areq)
 {
 	struct mmc_test_async_req *test_async =
 		container_of(areq, struct mmc_test_async_req, areq);
+	int ret;
 
 	mmc_test_wait_busy(test_async->test);
 
-	return mmc_test_check_result(test_async->test, areq->mrq);
+	/*
+	 * FIXME: this would earlier just casts a regular error code,
+	 * either of the kernel type -ERRORCODE or the local test framework
+	 * RESULT_* errorcode, into an enum mmc_blk_status and return as
+	 * result check. Instead, convert it to some reasonable type by just
+	 * returning either MMC_BLK_SUCCESS or MMC_BLK_CMD_ERR.
+	 * If possible, a reasonable error code should be returned.
+	 */
+	ret = mmc_test_check_result(test_async->test, areq->mrq);
+	if (ret)
+		return MMC_BLK_CMD_ERR;
+
+	return MMC_BLK_SUCCESS;
 }
 
 /*
@@ -817,6 +830,7 @@ static int mmc_test_nonblock_transfer(struct mmc_test_card *test,
 	struct mmc_async_req *done_areq;
 	struct mmc_async_req *cur_areq = &test_areq[0].areq;
 	struct mmc_async_req *other_areq = &test_areq[1].areq;
+	enum mmc_blk_status status;
 	int i;
 	int ret;
 
@@ -834,10 +848,12 @@ static int mmc_test_nonblock_transfer(struct mmc_test_card *test,
 	for (i = 0; i < count; i++) {
 		mmc_test_prepare_mrq(test, cur_areq->mrq, sg, sg_len, dev_addr,
 				     blocks, blksz, write);
-		done_areq = mmc_start_req(test->card->host, cur_areq, &ret);
+		done_areq = mmc_start_req(test->card->host, cur_areq, &status);
 
-		if (ret || (!done_areq && i > 0))
+		if (status != MMC_BLK_SUCCESS || (!done_areq && i > 0)) {
+			ret = RESULT_FAIL;
 			goto err;
+		}
 
 		if (done_areq) {
 			if (done_areq->mrq == &mrq2)
@@ -851,7 +867,9 @@ static int mmc_test_nonblock_transfer(struct mmc_test_card *test,
 		dev_addr += blocks;
 	}
 
-	done_areq = mmc_start_req(test->card->host, NULL, &ret);
+	done_areq = mmc_start_req(test->card->host, NULL, &status);
+	if (status != MMC_BLK_SUCCESS)
+		ret = RESULT_FAIL;
 
 	return ret;
 err:
@@ -2351,6 +2369,7 @@ static int mmc_test_ongoing_transfer(struct mmc_test_card *test,
 	struct mmc_request *mrq;
 	unsigned long timeout;
 	bool expired = false;
+	enum mmc_blk_status blkstat = MMC_BLK_SUCCESS;
 	int ret = 0, cmd_ret;
 	u32 status = 0;
 	int count = 0;
@@ -2378,9 +2397,11 @@ static int mmc_test_ongoing_transfer(struct mmc_test_card *test,
 
 	/* Start ongoing data request */
 	if (use_areq) {
-		mmc_start_req(host, &test_areq.areq, &ret);
-		if (ret)
+		mmc_start_req(host, &test_areq.areq, &blkstat);
+		if (blkstat != MMC_BLK_SUCCESS) {
+			ret = RESULT_FAIL;
 			goto out_free;
+		}
 	} else {
 		mmc_wait_for_req(host, mrq);
 	}
@@ -2413,10 +2434,13 @@ static int mmc_test_ongoing_transfer(struct mmc_test_card *test,
 	} while (repeat_cmd && R1_CURRENT_STATE(status) != R1_STATE_TRAN);
 
 	/* Wait for data request to complete */
-	if (use_areq)
-		mmc_start_req(host, NULL, &ret);
-	else
+	if (use_areq) {
+		mmc_start_req(host, NULL, &blkstat);
+		if (blkstat != MMC_BLK_SUCCESS)
+			ret = RESULT_FAIL;
+	} else {
 		mmc_wait_for_req_done(test->card->host, mrq);
+	}
 
 	/*
 	 * For cap_cmd_during_tfr request, upper layer must send stop if