From 04a2ea248f58b3b6216d0cd0a6b8698df8b14355 Mon Sep 17 00:00:00 2001 From: Jean-Jacques Hiblot Date: Thu, 21 Sep 2017 16:30:08 +0200 Subject: [PATCH] mmc: disable UHS modes if Vcc cannot be switched on and off If a power cycle cannot be done on Vcc, it is safer not to try the UHS modes because we wouldn't be able to recover from an error occurring during the UHS initialization. Signed-off-by: Jean-Jacques Hiblot --- drivers/mmc/mmc.c | 19 ++++++++++++++++--- include/mmc.h | 1 + 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index fe31540ba2..dbd95946ea 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -1451,7 +1451,7 @@ static int sd_select_mode_and_width(struct mmc *mmc) if (err) return err; /* Restrict card's capabilities by what the host can do */ - caps = mmc->card_caps & (mmc->cfg->host_caps | MMC_MODE_1BIT); + caps = mmc->card_caps & (mmc->host_caps | MMC_MODE_1BIT); if (!uhs_en) caps &= ~UHS_CAPS; @@ -1599,7 +1599,7 @@ static int mmc_select_mode_and_width(struct mmc *mmc) return err; /* Restrict card's capabilities by what the host can do */ - mmc->card_caps &= (mmc->cfg->host_caps | MMC_MODE_1BIT); + mmc->card_caps &= (mmc->host_caps | MMC_MODE_1BIT); /* Only version 4 of MMC supports wider bus widths */ if (mmc->version < MMC_VERSION_4) @@ -2182,6 +2182,8 @@ int mmc_start_init(struct mmc *mmc) bool uhs_en = supports_uhs(mmc->cfg->host_caps); int err; + mmc->host_caps = mmc->cfg->host_caps; + /* we pretend there's no card when init is NULL */ no_card = mmc_getcd(mmc) == 0; #if !CONFIG_IS_ENABLED(DM_MMC) @@ -2205,7 +2207,18 @@ int mmc_start_init(struct mmc *mmc) if (err) return err; - err = mmc_power_on(mmc); + err = mmc_power_cycle(mmc); + if (err) { + /* + * if power cycling is not supported, we should not try + * to use the UHS modes, because we wouldn't be able to + * recover from an error during the UHS initialization. + */ + debug("Unable to do a full power cycle. Disabling the UHS modes for safety\n"); + uhs_en = false; + mmc->host_caps &= ~UHS_CAPS; + err = mmc_power_on(mmc); + } if (err) return err; diff --git a/include/mmc.h b/include/mmc.h index ba4a13e861..59ea363ea2 100644 --- a/include/mmc.h +++ b/include/mmc.h @@ -544,6 +544,7 @@ struct mmc { uint clock; enum mmc_voltage signal_voltage; uint card_caps; + uint host_caps; uint ocr; uint dsr; uint dsr_imp; -- 2.39.5