Commit e83b7a8a authored by Guennadi Liakhovetski's avatar Guennadi Liakhovetski Committed by Chris Ball
Browse files

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



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: default avatarGuennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Tested-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 19f1ba51

drivers/mmc/host/tmio_mmc.h

+18 −2
Original line number Diff line number Diff line
@@ -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);

drivers/mmc/host/tmio_mmc_pio.c

+17 −10
Original line number Diff line number Diff line
@@ -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)

		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)

CRA Git | Maintained and supported by SUSTech CRA and CCSE