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| 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 /include/linux/mmc/host.h | |
| parent | 44669034815a7ad263542ac605c581a10b22d146 (diff) | |
| download | lwn-7c8a2829c22a270acadc6aa3a937e2e7956b19f5.tar.gz lwn-7c8a2829c22a270acadc6aa3a937e2e7956b19f5.zip | |
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>
Diffstat (limited to 'include/linux/mmc/host.h')
| -rw-r--r-- | include/linux/mmc/host.h | 3 |
1 files changed, 3 insertions, 0 deletions
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); |