mmc: core: move ->request() call from atomic context

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>

Author: ahunter6

drivers/mmc/core/core.c

@@ -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);
+}
 }
 
 /**