From: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
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@xxxxxxxxxx>
---
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 ba821fe..0b6141d 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);
}
--
1.7.9
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