Hi Guennadi,
Thanks for the patch.
On Monday 22 April 2013 16:14:40 Guennadi Liakhovetski wrote:
> 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.
>
> Reported-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@xxxxxxxxx>
>
> ---
> drivers/mmc/host/tmio_mmc.h | 20 ++++++++++++++++++--
> drivers/mmc/host/tmio_mmc_pio.c | 16 +++++++++-------
> 2 files changed, 27 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
> index d857f5c..3cc589a 100644
> --- a/drivers/mmc/host/tmio_mmc.h
> +++ b/drivers/mmc/host/tmio_mmc.h
> @@ -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);
> diff --git a/drivers/mmc/host/tmio_mmc_pio.c
> b/drivers/mmc/host/tmio_mmc_pio.c index f508ecb..d442eab 100644
> --- a/drivers/mmc/host/tmio_mmc_pio.c
> +++ b/drivers/mmc/host/tmio_mmc_pio.c
> @@ -859,25 +859,27 @@ 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);
> }
> 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) {
Maybe host->power != TMIO_MMC_OFF_STOP ?
Otherwise the patch looks good to me.
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> struct tmio_mmc_data *pdata = host->pdata;
> - if (ios->power_mode == MMC_POWER_OFF)
> + 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;
> + }
> tmio_mmc_clk_stop(host);
> - host->power = false;
> pm_runtime_put(dev);
> if (pdata->clk_disable)
> pdata->clk_disable(host->pdev);
> @@ -1025,7 +1027,7 @@ 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)
--
Regards,
Laurent Pinchart
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