diff options
| author | Ziyuan Xu <xzy.xu@rock-chips.com> | 2016-05-26 08:50:32 +0300 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2016-07-25 11:34:09 +0300 |
| commit | 649c6059d2371fef886a8f967e21416204723d63 (patch) | |
| tree | 7915ac283672e0acf55916d41479365c36fa381c /drivers/mmc/core/mmc.c | |
| parent | 987aa5f8059613bf85cbb6f64ffbd34f5cb7a9d1 (diff) | |
| download | linux-649c6059d2371fef886a8f967e21416204723d63.tar.xz | |
mmc: mmc: Fix HS switch failure in mmc_select_hs400()
To slove the issue which was found on gru board for hs400.
[ 4.616946] sdhci: Secure Digital Host Controller Interface driver
[ 4.623135] sdhci: Copyright(c) Pierre Ossman
[ 4.722575] sdhci-pltfm: SDHCI platform and OF driver helper
[ 4.730962] sdhci-arasan fe330000.sdhci: No vmmc regulator found
[ 4.737444] sdhci-arasan fe330000.sdhci: No vqmmc regulator found
[ 4.774930] mmc0: SDHCI controller on fe330000.sdhci [fe330000.sdhci] using ADMA
[ 4.980295] mmc0: switch to high-speed from hs200 failed, err:-84
[ 4.986487] mmc0: error -84 whilst initialising MMC card
We should change HS400 mode selection timing to meet JEDEC
specification. The JEDEC 5.1 said that change the frequency to <= 52MHZ
after HS_TIMING switch. Refer to section 6.6.2.3 "HS400" timing mode
selection:
Set the "Timing Interface" parameter in the HS_TIMING[185] field of the
Extended CSD register to 0x1 to switch to High Speed mode and then set
the clock frequency to a value not greater than 52MHZ.
Signed-off-by: Ziyuan Xu <xzy.xu@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc/core/mmc.c')
| -rw-r--r-- | drivers/mmc/core/mmc.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 490229e4010c..900b9f935297 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1082,10 +1082,6 @@ static int mmc_select_hs400(struct mmc_card *card) host->ios.bus_width == MMC_BUS_WIDTH_8)) return 0; - /* Reduce frequency to HS frequency */ - max_dtr = card->ext_csd.hs_max_dtr; - mmc_set_clock(host, max_dtr); - /* Switch card to HS mode */ val = EXT_CSD_TIMING_HS; err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, @@ -1101,6 +1097,10 @@ static int mmc_select_hs400(struct mmc_card *card) /* Set host controller to HS timing */ mmc_set_timing(card->host, MMC_TIMING_MMC_HS); + /* Reduce frequency to HS frequency */ + max_dtr = card->ext_csd.hs_max_dtr; + mmc_set_clock(host, max_dtr); + err = mmc_switch_status(card); if (err) goto out_err; |