On 3/19/2015 6:51 PM, Peng.Fan@freescale.com wrote:
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@lists.denx.de] On Behalf Of Andrew Gabbasov Sent: Thursday, March 19, 2015 8:44 PM To: u-boot@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@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;
--
Here's another patch that solves the problem a little earlier. It has this disadvantage of being slightly bigger, though it makes the code look better.
https://github.com/boundarydevices/u-boot-imx6/commit/c0260ca
I'll ack any version as they all seem to solve the problem.
Troy