From: Kyungmin Seo <kyungmin.seo@intel.com>
To: ulf.hansson@linaro.org, kyungmin.seo@intel.com
Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] mmc: mmc: Fix the timing for clock changing in mmc
Date: Wed, 12 Feb 2020 11:42:20 +0900 [thread overview]
Message-ID: <20200212024220.GA32111@seokyung-mobl1> (raw)
The clock has to be changed after sending CMD6 for HS mode selection in
mmc_hs400_to_hs200() function.
The JEDEC 5.0 and 5.1 said that "High-speed" mode selection has to
enable the the high speed mode timing in the Device, before chaning the
clock frequency to a frequency between 26MHz and 52MHz.
Signed-off-by: Kyungmin Seo <kyungmin.seo@intel.com>
---
drivers/mmc/core/mmc.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 3486bc7fbb64..98640b51c73e 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1196,10 +1196,6 @@ int mmc_hs400_to_hs200(struct mmc_card *card)
int err;
u8 val;
- /* Reduce frequency to HS */
- max_dtr = card->ext_csd.hs_max_dtr;
- mmc_set_clock(host, max_dtr);
-
/* Switch HS400 to HS DDR */
val = EXT_CSD_TIMING_HS;
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING,
@@ -1210,6 +1206,10 @@ int mmc_hs400_to_hs200(struct mmc_card *card)
mmc_set_timing(host, MMC_TIMING_MMC_DDR52);
+ /* Reduce frequency to HS */
+ max_dtr = card->ext_csd.hs_max_dtr;
+ mmc_set_clock(host, max_dtr);
+
err = mmc_switch_status(card);
if (err)
goto out_err;
--
2.17.1
next reply other threads:[~2020-02-12 2:40 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-12 2:42 Kyungmin Seo [this message]
2020-03-04 11:08 ` [PATCH] mmc: mmc: Fix the timing for clock changing in mmc Ulf Hansson
2020-03-05 8:57 ` Seo, Kyungmin
2020-03-05 15:17 ` Ulf Hansson
2020-03-10 4:27 ` Seo, Kyungmin
2020-03-10 9:05 ` Ulf Hansson
2020-03-10 10:44 ` Adrian Hunter
2020-03-10 15:41 ` Ulf Hansson
2020-03-11 2:13 ` Chaotian Jing
2020-03-11 8:57 ` Ulf Hansson
2020-03-11 9:59 ` Adrian Hunter
2020-03-11 14:06 ` Ulf Hansson
2020-03-11 14:43 ` Adrian Hunter
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