mmc: core: move ->request() call from atomic context
Adrian Hunter [Mon, 3 Oct 2011 12:33:33 +0000 (15:33 +0300)]
mmc_request_done() is sometimes called from interrupt or other atomic
context.  Mostly all mmc_request_done() does is complete(), however it
contains code to retry on error, which uses ->request().  As the error
path is certainly not performance critical, this may be moved to the
waiting function mmc_wait_for_req_done().

This allows ->request() to use runtime PM get_sync() and guarantee it
is never in an atomic context.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ulf Hansson <ulf.hansson@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/core.c

index 9698d8a..ec76949 100644 (file)
@@ -141,12 +141,12 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
        }
 
        if (err && cmd->retries) {
-               pr_debug("%s: req failed (CMD%u): %d, retrying...\n",
-                       mmc_hostname(host), cmd->opcode, err);
-
-               cmd->retries--;
-               cmd->error = 0;
-               host->ops->request(host, mrq);
+               /*
+                * Request starter must handle retries - see
+                * mmc_wait_for_req_done().
+                */
+               if (mrq->done)
+                       mrq->done(mrq);
        } else {
                mmc_should_fail_request(host, mrq);
 
@@ -253,7 +253,21 @@ static void __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
 static void mmc_wait_for_req_done(struct mmc_host *host,
                                  struct mmc_request *mrq)
 {
-       wait_for_completion(&mrq->completion);
+       struct mmc_command *cmd;
+
+       while (1) {
+               wait_for_completion(&mrq->completion);
+
+               cmd = mrq->cmd;
+               if (!cmd->error || !cmd->retries)
+                       break;
+
+               pr_debug("%s: req failed (CMD%u): %d, retrying...\n",
+                        mmc_hostname(host), cmd->opcode, cmd->error);
+               cmd->retries--;
+               cmd->error = 0;
+               host->ops->request(host, mrq);
+       }
 }
 
 /**