diff options
| author | Per Forlin <per.forlin@linaro.org> | 2011-08-29 15:35:58 +0200 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2011-10-26 16:32:04 -0400 |
| commit | 7c8a2829c22a270acadc6aa3a937e2e7956b19f5 (patch) | |
| tree | b787b429a1bd01f364e752fe5b52e2f95cb46875 | |
| parent | 44669034815a7ad263542ac605c581a10b22d146 (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>
| -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 45ea968e7dd1..0b4c2ed22bce 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -320,8 +320,14 @@ 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 4c4bddf5ef61..340cc0c9409f 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); |