linux-kernel - [PATCH] Move the judgement of timeout into mmc_switch_status

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Date:	Mon, 28 Dec 2015 02:07:26 +0000 (GMT)
From:	Youngjin Jang <yj84.jang@...sung.com>
To:	ulf.hansson@...aro.org, linux-mmc@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc:	demon.lee@...sung.com, js07.lee@...sung.com
Subject: [PATCH] Move the judgement of timeout into mmc_switch_status_error()

__mmc_switch() is possible to misjudge error.

Although jiffies was overed timeout,
the chance about "R1_CURRENT_STATE(status) != R1_STATE_PRG" is exists.
In other words, Successful completion of CMD6 with timeout error.

Kernel expects failure of __mmc_switch,
but card is completed CMD6 in this case.
It makes mismatch status between mmc subsystem and mmc card.

Especially, in case of partition switch,
If timeout occurs with normal status of CMD13 response unfortunatley,
"main_md->curr" will not be set, even card switched successfully.

Checking state of mmc card is needed when judging an timeout error,
if it is just timeout or timeout with error.

Reviewed-by: Jungseung Lee <js07.lee@...sung.com>
Signed-off-by: Youngjin Jang <yj84.jang@...sung.com>
---
 drivers/mmc/core/mmc_ops.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 1f44426..033f475 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -456,6 +456,8 @@ int mmc_switch_status_error(struct mmc_host *host, u32 status)
 		if (status & R1_SPI_ILLEGAL_COMMAND)
 			return -EBADMSG;
 	} else {
+		if (R1_CURRENT_STATE(status) == R1_STATE_PRG)
+			return -ETIMEDOUT;
 		if (status & 0xFDFFA000)
 			pr_warn("%s: unexpected status %#x after switch\n",
 				mmc_hostname(host), status);
@@ -568,8 +570,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
 		if (time_after(jiffies, timeout)) {
 			pr_err("%s: Card stuck in programming state! %s\n",
 				mmc_hostname(host), __func__);
-			err = -ETIMEDOUT;
-			goto out;
+			break;
 		}
 	} while (R1_CURRENT_STATE(status) == R1_STATE_PRG);

-- 
1.7.9.5