[U-Boot] [PATCH 4/6] mmc: Continue polling MMC card for OCR only if it is still not ready

Peng.Fan at freescale.com Peng.Fan at freescale.com
Fri Mar 20 02:51:30 CET 2015


Hi, Andrew

There is already a patch to fix this issue.
Patchwork: https://patchwork.ozlabs.org/patch/451775/

Regards,
Peng.

-----Original Message-----
From: U-Boot [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Andrew Gabbasov
Sent: Thursday, March 19, 2015 8:44 PM
To: u-boot at lists.denx.de
Subject: [U-Boot] [PATCH 4/6] mmc: Continue polling MMC card for OCR only if it is still not ready

Some MMC cards come to ready state quite quickly, so that the respective flag appears to be set in mmc_send_op_cond already. In this case trying to continue polling the card with CMD1 in mmc_complete_op_cond is incorrect and may lead to unpredictable results. So check the flag before polling and skip it appropriately.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov at mentor.com>
---
 drivers/mmc/mmc.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index d073d79..42af47c 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -403,15 +403,17 @@ static int mmc_complete_op_cond(struct mmc *mmc)
 	int err;
 
 	mmc->op_cond_pending = 0;
-	start = get_timer(0);
-	do {
-		err = mmc_send_op_cond_iter(mmc, 1);
-		if (err)
-			return err;
-		if (get_timer(start) > timeout)
-			return UNUSABLE_ERR;
-		udelay(100);
-	} while (!(mmc->ocr & OCR_BUSY));
+	if (!(mmc->ocr & OCR_BUSY)) {
+		start = get_timer(0);
+		do {
+			err = mmc_send_op_cond_iter(mmc, 1);
+			if (err)
+				return err;
+			if (get_timer(start) > timeout)
+				return UNUSABLE_ERR;
+			udelay(100);
+		} while (!(mmc->ocr & OCR_BUSY));
+	}
 
 	if (mmc_host_is_spi(mmc)) { /* read OCR for spi */
 		cmd.cmdidx = MMC_CMD_SPI_READ_OCR;
--
2.1.0

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