diff options
| author | Per Forlin <per.forlin@linaro.org> | 2011-08-29 15:35:58 +0200 |
|---|---|---|
| committer | Robert Marklund <robert.marklund@stericsson.com> | 2011-10-27 16:07:57 +0200 |
| commit | 6f7b31634839cbc115f42787e0c4027332e015b2 (patch) | |
| tree | acbfa364f42a6ac7b7c75d3ae6157a7fe9ab6b64 | |
| parent | 49f9b3db2a7f8da006949b256c7a9419671184bb (diff) | |
mmc: core: clarify how to use post_req in case of errors
The err condition in post_req() is set to undo a call made to pre_req()
that hasn't been started yet. The err condition is not set if an MMC
request returns an error.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Change-Id: Ie91c9868301c654ae27937b666089d82017b75f2
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/33433
Reviewed-by: Ulf HANSSON <ulf.hansson@stericsson.com>
Tested-by: Ulf HANSSON <ulf.hansson@stericsson.com>
| -rw-r--r-- | drivers/mmc/core/core.c | 6 | ||||
| -rw-r--r-- | include/linux/mmc/host.h | 3 |
2 files changed, 9 insertions, 0 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index e7ae3d91f9c..ddb5b8c6521 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -319,8 +319,14 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host, mmc_wait_for_req_done(host, host->areq->mrq); err = host->areq->err_check(host->card, host->areq); if (err) { + /* post process the completed failed request */ mmc_post_req(host, host->areq->mrq, 0); if (areq) + /* + * Cancel the new prepared request, because + * it can't run until the failed + * request has been properly handled. + */ mmc_post_req(host, areq->mrq, -EINVAL); host->areq = NULL; diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index aaba58d7372..e2f7d6d6c62 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -109,6 +109,9 @@ struct mmc_host_ops { * It is optional for the host to implement pre_req and post_req in * order to support double buffering of requests (prepare one * request while another request is active). + * pre_req() must always be followed by a post_req(). + * To undo a call made to pre_req(), call post_req() with + * a nonzero err condition. */ void (*post_req)(struct mmc_host *host, struct mmc_request *req, int err); |