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>

1 files changed, 21 insertions, 7 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 9698d8a2e166..ec7694903008 100644
--- a/drivers/mmc/core/core.c
+++ b/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);
+        }
 }
 
 /**