From 4f25580fb84d934d7ecffa3c0aa8f10f7e23af92 Mon Sep 17 00:00:00 2001 From: Shawn Lin Date: Fri, 30 Sep 2016 14:18:59 +0800 Subject: [PATCH] mmc: core: changes frequency to hs_max_dtr when selecting hs400es Per JESD84-B51 P49, Host need to change frequency to <=52MHz after setting HS_TIMING to 0x1, and host may changes frequency to <= 200MHz after setting HS_TIMING to 0x3. That means the card expects the clock rate to increase from the current used f_init (which is less than 400KHz, but still being less than 52MHz) to 52MHz, otherwise we find some eMMC devices significantly report failure when sending status. Reported-by: Xiao Yao Signed-off-by: Shawn Lin Reviewed-by: Douglas Anderson Signed-off-by: Ulf Hansson --- drivers/mmc/core/mmc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index f4ed5accafd0..39fc5b2b96c5 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1282,6 +1282,8 @@ static int mmc_select_hs400es(struct mmc_card *card) if (err) goto out_err; + mmc_set_clock(host, card->ext_csd.hs_max_dtr); + err = mmc_switch_status(card); if (err) goto out_err; -- 2.20.1