From f8e4df85374bb4cb7b0a61d93c7de429d9abe12d Mon Sep 17 00:00:00 2001 From: Jaehoon Chung Date: Tue, 14 Dec 2010 18:05:38 +0900 Subject: [PATCH] mmc: Add comment for Feedback clock enable Signed-off-by: Jaehoon Chung --- drivers/mmc/s5p_mmc.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/mmc/s5p_mmc.c b/drivers/mmc/s5p_mmc.c index f60e557..5767f37 100644 --- a/drivers/mmc/s5p_mmc.c +++ b/drivers/mmc/s5p_mmc.c @@ -397,6 +397,13 @@ static void mmc_set_ios(struct mmc *mmc) (1 << 14) | /* Feedback Clock Enable for Rx Clock */ (1 << 8); /* SDCLK hold enable */ + /* + * When entered boot mode, we used Tx Feedback Delay. + * So We need to set Feedback clock enable for Tx Clock. + * In normal mode, we need not Tx clock. + * If set that in normal mode, we should find out some problem + * (CRC error, Timeout error, etc..) + */ if (mmc->boot_config & 0x7) val |= (1 << 15); /* Feedback Clock Enable for Tx Clock */ -- 2.7.4