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authorShawn Lin <shawn.lin@rock-chips.com>2016-09-30 14:18:59 +0800
committerUlf Hansson <ulf.hansson@linaro.org>2016-10-10 14:01:15 +0200
commit4f25580fb84d934d7ecffa3c0aa8f10f7e23af92 (patch)
tree624c64cb0d179ff5ef5732ce4f7d58eaf4302b59 /drivers/mmc
parent1720d3545b772c49b2975eeb3b8f4d3f56dc2085 (diff)
downloadlinux-4f25580fb84d934d7ecffa3c0aa8f10f7e23af92.tar.bz2
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 <xiaoyao@rock-chips.com> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/core/mmc.c2
1 files changed, 2 insertions, 0 deletions
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;