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>
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 45ea968..0b4c2ed 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -320,8 +320,14 @@
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;