mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-08-24 01:41:39 +00:00
Code Issues Releases Wiki Activity

mmc: tmio: fix unbalanced power-on calls with clock-gating enabled

Browse source 
With MMC clock gating enabled the MMC core currently calls MMC host driver's
.set_ios() method with .power_mode == MMC_POWER_ON and the clock value set
either to 0 or to the target rate. The tmio MMC driver then wrongly
translates the latter calls to card slot power-on requests, even when the
slot already was on. This patch fixes the driver to avoid needlessly
incrementing power-supplying regulator's use count.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Guennadi Liakhovetski 2013-06-06 16:35:44 +02:00 committed by Chris Ball
parent 19f1ba51c7
commit e83b7a8acc
2 changed files with 35 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
drivers/mmc/host/tmio_mmc.h
View file

@ -40,6 +40,22 @@
struct tmio_mmc_data;
/*
* We differentiate between the following 3 power states:
* 1. card slot powered off, controller stopped. This is used, when either there
* is no card in the slot, or the card really has to be powered down.
* 2. card slot powered on, controller stopped. This is used, when a card is in
* the slot, but no activity is currently taking place. This is a power-
* saving mode with card-state preserved. This state can be entered, e.g.
* when MMC clock-gating is used.
* 3. card slot powered on, controller running. This is the actual active state.
*/
enum tmio_mmc_power {
TMIO_MMC_OFF_STOP, /* card power off, controller stopped */
TMIO_MMC_ON_STOP, /* card power on, controller stopped */
TMIO_MMC_ON_RUN, /* card power on, controller running */
};
struct tmio_mmc_host {
void __iomem *ctl;
unsigned long bus_shift;
@ -48,8 +64,8 @@ struct tmio_mmc_host {
struct mmc_data *data;
struct mmc_host *mmc;
/* Controller power state */
bool power;
/* Controller and card power state */
enum tmio_mmc_power power;
/* Callbacks for clock / power control */
void (*set_pwr)(struct platform_device *host, int state);

27
drivers/mmc/host/tmio_mmc_pio.c
View file

@ -859,7 +859,7 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
* is kept positive, so no suspending actually takes place.
*/
if (ios->power_mode == MMC_POWER_ON && ios->clock) {
if (!host->power) {
if (host->power != TMIO_MMC_ON_RUN) {
tmio_mmc_clk_update(mmc);
pm_runtime_get_sync(dev);
if (host->resuming) {
@ -868,27 +868,34 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
}
}
tmio_mmc_set_clock(host, ios->clock);
if (!host->power) {
if (host->power == TMIO_MMC_OFF_STOP)
/* power up SD card and the bus */
tmio_mmc_power_on(host, ios->vdd);
host->power = true;
}
host->power = TMIO_MMC_ON_RUN;
/* start bus clock */
tmio_mmc_clk_start(host);
} else if (ios->power_mode != MMC_POWER_UP) {
if (host->power) {
struct tmio_mmc_data *pdata = host->pdata;
if (ios->power_mode == MMC_POWER_OFF)
struct tmio_mmc_data *pdata = host->pdata;
unsigned int old_power = host->power;
if (old_power != TMIO_MMC_OFF_STOP) {
if (ios->power_mode == MMC_POWER_OFF) {
tmio_mmc_power_off(host);
host->power = TMIO_MMC_OFF_STOP;
} else {
host->power = TMIO_MMC_ON_STOP;
}
}
if (old_power == TMIO_MMC_ON_RUN) {
tmio_mmc_clk_stop(host);
host->power = false;
pm_runtime_put(dev);
if (pdata->clk_disable)
pdata->clk_disable(host->pdev);
}
}
if (host->power) {
if (host->power != TMIO_MMC_OFF_STOP) {
switch (ios->bus_width) {
case MMC_BUS_WIDTH_1:
sd_ctrl_write16(host, CTL_SD_MEM_CARD_OPT, 0x80e0);
@ -1029,7 +1036,7 @@ int tmio_mmc_host_probe(struct tmio_mmc_host **host,
mmc->caps & MMC_CAP_NONREMOVABLE ||
mmc->slot.cd_irq >= 0);
_host->power = false;
_host->power = TMIO_MMC_OFF_STOP;
pm_runtime_enable(&pdev->dev);
ret = pm_runtime_resume(&pdev->dev);
if (ret < 0)