[PATCH] mmc : Use wait_for_completion_timeout() instead of wait_for_completion in case of write.

[Namjae Jeon <linkinjeon@gmail.com>]

host controller can not rise timeout interrupt in write not read in DMA status. 
because host can just know whether card is finish to program to use busy line. 
If unstable card is keep holding busy line while writing using DMA.
hang problem happen by wait_for_completion. so I think that mmc driver need some exception to avoid this problem.
I suggest to use wait_for_completion_timeout instead of wait_for_completion.

Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
---
 drivers/mmc/core/core.c |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 557856b..0fe83d3 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -253,7 +253,20 @@ 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);
+	unsigned int timeout_us;
+
+	if ((mrq->data != NULL) && (mrq->data->flags & MMC_DATA_WRITE)) {
+		timeout_us = mrq->data->timeout_ns / 1000;
+		if (mmc_host_clk_rate(host))
+			timeout_us += mrq->data->timeout_clks * 1000 /
+				(mmc_host_clk_rate(host) / 1000);
+		if (!timeout_us)
+			timeout_us = 1000000;
+		if (!wait_for_completion_timeout(&mrq->completion,
+				usecs_to_jiffies(timeout_us)))
+			mrq->cmd->error = -ETIMEDOUT;
+	} else
+		wait_for_completion(&mrq->completion);
 }
 
 /**
-- 
1.7.4.4