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| author | Ulf Hansson <ulf.hansson@linaro.org> | 2012-05-09 16:15:26 +0200 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2012-05-09 12:55:01 -0400 |
| commit | fa5501890d8974301042e0202d342a6cbe8609f4 (patch) | |
| tree | ae127577d2591e22eed2621d87d1b289e016f3f6 /drivers/mmc | |
| parent | 95dcc2cb6c9c84555c29187f8b7cf39e83991a29 (diff) | |
| download | linux-fa5501890d8974301042e0202d342a6cbe8609f4.tar.gz linux-fa5501890d8974301042e0202d342a6cbe8609f4.tar.xz linux-fa5501890d8974301042e0202d342a6cbe8609f4.zip | |
mmc: core: Prevent eMMC VCC supply to be cut from late init
For eMMC cards that has been initialized from a bootloader,
the VCC voltage supply must not be cut in an uncontrolled
manner, without first sending SLEEP or POWEROFF_NOTIFY.
The regulator_init_complete late initcall, may cut the VCC
regulator if it's reference counter is zero. To be able to
prevent the regulator from being cut, mmc_start_host, which
should execute at device init and thus before late init,
calls mmc_power_up. Then the host driver is able to increase
the reference to the regulator.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/core/core.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index ba821fe70bca..0b6141d29dbd 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -42,6 +42,7 @@ #include "sdio_ops.h" static struct workqueue_struct *workqueue; +static const unsigned freqs[] = { 400000, 300000, 200000, 100000 }; /* * Enabling software CRCs on the data blocks can be a significant (30%) @@ -1157,6 +1158,9 @@ static void mmc_power_up(struct mmc_host *host) { int bit; + if (host->ios.power_mode == MMC_POWER_ON) + return; + mmc_host_clk_hold(host); /* If ocr is set, we use it */ @@ -1199,6 +1203,10 @@ static void mmc_power_up(struct mmc_host *host) void mmc_power_off(struct mmc_host *host) { int err = 0; + + if (host->ios.power_mode == MMC_POWER_OFF) + return; + mmc_host_clk_hold(host); host->ios.clock = 0; @@ -2005,7 +2013,6 @@ EXPORT_SYMBOL(mmc_detect_card_removed); void mmc_rescan(struct work_struct *work) { - static const unsigned freqs[] = { 400000, 300000, 200000, 100000 }; struct mmc_host *host = container_of(work, struct mmc_host, detect.work); int i; @@ -2044,8 +2051,12 @@ void mmc_rescan(struct work_struct *work) */ mmc_bus_put(host); - if (host->ops->get_cd && host->ops->get_cd(host) == 0) + if (host->ops->get_cd && host->ops->get_cd(host) == 0) { + mmc_claim_host(host); + mmc_power_off(host); + mmc_release_host(host); goto out; + } mmc_claim_host(host); for (i = 0; i < ARRAY_SIZE(freqs); i++) { @@ -2063,7 +2074,8 @@ void mmc_rescan(struct work_struct *work) void mmc_start_host(struct mmc_host *host) { - mmc_power_off(host); + host->f_init = max(freqs[0], host->f_min); + mmc_power_up(host); mmc_detect_change(host, 0); } |