Re: [PATCH v4 1/1] mmc: dw_mmc: Add runtime pm to dw_mmc

From: Ulf Hansson
Date: Thu Apr 09 2015 - 05:43:58 EST


On 19 March 2015 at 14:44, Karol Wrona <k.wrona@xxxxxxxxxxx> wrote:
> This patch adds runtime pm handling to dw_mmc.
> It mainly uses mci_request/mci_request_end for mmc host state information.
> The goal of the runtime pm in dw_mmc host is mainly for giving an information
> for containing it power domain about its activity.
>
> Signed-off-by: Karol Wrona <k.wrona@xxxxxxxxxxx>
> Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
> drivers/mmc/host/dw_mmc.c | 117 +++++++++++++++++++++++++++++++++++++++++----
> drivers/mmc/host/dw_mmc.h | 2 +
> 2 files changed, 110 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 47dfd0e..086cabc 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -38,6 +38,7 @@
> #include <linux/of.h>
> #include <linux/of_gpio.h>
> #include <linux/mmc/slot-gpio.h>
> +#include <linux/pm_runtime.h>
>
> #include "dw_mmc.h"
>
> @@ -104,6 +105,29 @@ static bool dw_mci_reset(struct dw_mci *host);
> static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset);
> static int dw_mci_card_busy(struct mmc_host *mmc);
>
> +#ifdef CONFIG_PM
> +static inline int dw_mci_pm_runtime_get(struct dw_mci *host)
> +{
> + return pm_runtime_get_sync(host->dev);
> +}
> +
> +static inline int dw_mci_pm_runtime_put(struct dw_mci *host)
> +{
> + pm_runtime_mark_last_busy(host->dev);
> + return pm_runtime_put_autosuspend(host->dev);
> +}
> +#else /* !CONFIG_PM */
> +static inline int dw_mci_pm_runtime_get(struct dw_mci *host)
> +{
> + return 0;
> +}
> +
> +static inline int dw_mci_pm_runtime_put(struct dw_mci *host)
> +{
> + return 0;
> +}
> +#endif /* CONFIG_PM */

Please remove these wrapper functions, I don't think they add something useful.

> +
> #if defined(CONFIG_DEBUG_FS)
> static int dw_mci_req_show(struct seq_file *s, void *v)
> {
> @@ -113,6 +137,8 @@ static int dw_mci_req_show(struct seq_file *s, void *v)
> struct mmc_command *stop;
> struct mmc_data *data;
>
> + dw_mci_pm_runtime_get(slot->host);
> +
> /* Make sure we get a consistent snapshot */
> spin_lock_bh(&slot->host->lock);
> mrq = slot->mrq;
> @@ -142,6 +168,8 @@ static int dw_mci_req_show(struct seq_file *s, void *v)
>
> spin_unlock_bh(&slot->host->lock);
>
> + dw_mci_pm_runtime_put(slot->host);
> +
> return 0;
> }
>
> @@ -1071,6 +1099,8 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
>
> WARN_ON(slot->mrq);
>
> + dw_mci_pm_runtime_get(host);
> +
> /*
> * The check for card presence and queueing of the request must be
> * atomic, otherwise the card could be removed in between and the
> @@ -1082,6 +1112,8 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
> spin_unlock_bh(&host->lock);
> mrq->cmd->error = -ENOMEDIUM;
> mmc_request_done(mmc, mrq);
> +
> + dw_mci_pm_runtime_put(host);
> return;
> }
>
> @@ -1109,6 +1141,8 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> slot->ctype = SDMMC_CTYPE_1BIT;
> }
>
> + dw_mci_pm_runtime_get(slot->host);
> +
> regs = mci_readl(slot->host, UHS_REG);
>
> /* DDR mode set */
> @@ -1139,7 +1173,7 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> dev_err(slot->host->dev,
> "failed to enable vmmc regulator\n");
> /*return, if failed turn on vmmc*/
> - return;
> + goto out;
> }
> }
> set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
> @@ -1192,6 +1226,9 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>
> if (slot->host->state == STATE_WAITING_CMD11_DONE && ios->clock != 0)
> slot->host->state = STATE_IDLE;
> +
> +out:
> + dw_mci_pm_runtime_put(slot->host);
> }
>
> static int dw_mci_card_busy(struct mmc_host *mmc)
> @@ -1199,12 +1236,16 @@ static int dw_mci_card_busy(struct mmc_host *mmc)
> struct dw_mci_slot *slot = mmc_priv(mmc);
> u32 status;
>
> + dw_mci_pm_runtime_get(slot->host);
> +
> /*
> * Check the busy bit which is low when DAT[3:0]
> * (the data lines) are 0000
> */
> status = mci_readl(slot->host, STATUS);
>
> + dw_mci_pm_runtime_put(slot->host);
> +
> return !!(status & SDMMC_STATUS_BUSY);
> }
>
> @@ -1215,7 +1256,9 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
> u32 uhs;
> u32 v18 = SDMMC_UHS_18V << slot->id;
> int min_uv, max_uv;
> - int ret;
> + int ret = 0;
> +
> + dw_mci_pm_runtime_get(host);
>
> /*
> * Program the voltage. Note that some instances of dw_mmc may use
> @@ -1239,12 +1282,16 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
> dev_dbg(&mmc->class_dev,
> "Regulator set error %d: %d - %d\n",
> ret, min_uv, max_uv);
> - return ret;
> +
> + goto out;
> }
> }
> mci_writel(host, UHS_REG, uhs);
>
> - return 0;
> +out:
> + dw_mci_pm_runtime_put(host);
> +
> + return ret;
> }
>
> static int dw_mci_get_ro(struct mmc_host *mmc)
> @@ -1253,6 +1300,8 @@ static int dw_mci_get_ro(struct mmc_host *mmc)
> struct dw_mci_slot *slot = mmc_priv(mmc);
> int gpio_ro = mmc_gpio_get_ro(mmc);
>
> + dw_mci_pm_runtime_get(slot->host);
> +
> /* Use platform get_ro function, else try on board write protect */
> if ((slot->quirks & DW_MCI_SLOT_QUIRK_NO_WRITE_PROTECT) ||
> (slot->host->quirks & DW_MCI_QUIRK_NO_WRITE_PROTECT))
> @@ -1263,6 +1312,8 @@ static int dw_mci_get_ro(struct mmc_host *mmc)
> read_only =
> mci_readl(slot->host, WRTPRT) & (1 << slot->id) ? 1 : 0;
>
> + dw_mci_pm_runtime_put(slot->host);
> +
> dev_dbg(&mmc->class_dev, "card is %s\n",
> read_only ? "read-only" : "read-write");
>
> @@ -1277,6 +1328,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
> struct dw_mci *host = slot->host;
> int gpio_cd = mmc_gpio_get_cd(mmc);
>
> + dw_mci_pm_runtime_get(host);
> +
> /* Use platform get_cd function, else try onboard card detect */
> if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
> present = 1;
> @@ -1296,6 +1349,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
> }
> spin_unlock_bh(&host->lock);
>
> + dw_mci_pm_runtime_put(host);
> +
> return present;
> }
>
> @@ -1304,6 +1359,8 @@ static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
> struct dw_mci_slot *slot = mmc_priv(mmc);
> struct dw_mci *host = slot->host;
>
> + dw_mci_pm_runtime_get(host);
> +
> /*
> * Low power mode will stop the card clock when idle. According to the
> * description of the CLKENA register we should disable low power mode
> @@ -1331,6 +1388,8 @@ static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
> SDMMC_CMD_PRV_DAT_WAIT, 0);
> }
> }
> +
> + dw_mci_pm_runtime_put(host);
> }
>
> static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
> @@ -1340,6 +1399,9 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
> unsigned long irqflags;
> u32 int_mask;
>
> + if (enb)
> + dw_mci_pm_runtime_get(slot->host);

Are sure this "get" will be properly balanced with below "put"?

> +
> spin_lock_irqsave(&host->irq_lock, irqflags);
>
> /* Enable/disable Slot Specific SDIO interrupt */
> @@ -1351,6 +1413,10 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
> mci_writel(host, INTMASK, int_mask);
>
> spin_unlock_irqrestore(&host->irq_lock, irqflags);
> +
> + /* If interrupt is enabled leave device active. */
> + if (!enb)
> + dw_mci_pm_runtime_put(slot->host);
> }
>
> static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> @@ -1360,8 +1426,13 @@ static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> const struct dw_mci_drv_data *drv_data = host->drv_data;
> int err = -ENOSYS;
>
> + dw_mci_pm_runtime_get(host);
> +
> if (drv_data && drv_data->execute_tuning)
> err = drv_data->execute_tuning(slot);
> +
> + dw_mci_pm_runtime_put(host);
> +
> return err;
> }
>
> @@ -1371,9 +1442,13 @@ static int dw_mci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios
> struct dw_mci *host = slot->host;
> const struct dw_mci_drv_data *drv_data = host->drv_data;
>
> + dw_mci_pm_runtime_get(host);
> +
> if (drv_data && drv_data->prepare_hs400_tuning)
> return drv_data->prepare_hs400_tuning(host, ios);
>
> + dw_mci_pm_runtime_put(host);
> +
> return 0;
> }
>
> @@ -1414,10 +1489,13 @@ static void dw_mci_request_end(struct dw_mci *host, struct mmc_request *mrq)
> } else {
> dev_vdbg(host->dev, "list empty\n");
>
> - if (host->state == STATE_SENDING_CMD11)
> + if (host->state == STATE_SENDING_CMD11) {
> host->state = STATE_WAITING_CMD11_DONE;
> - else
> + } else {
> + dw_mci_pm_runtime_put(host);
> +
> host->state = STATE_IDLE;
> + }
> }
>
> spin_unlock(&host->lock);
> @@ -2688,6 +2766,11 @@ int dw_mci_probe(struct dw_mci *host)
> return -ENODEV;
> }
>
> + pm_runtime_enable(host->dev);
> + pm_runtime_get_sync(host->dev);
> + pm_runtime_set_autosuspend_delay(host->dev, DWMMC_AUTOSUSPEND_DELAY);
> + pm_runtime_use_autosuspend(host->dev);

I think you shall change these four lines into:

pm_runtime_set_active();
pm_runtime_set_autosuspend_delay();
pm_runtime_use_autosuspend();
pm_runtime_enable();

And move them just before calling dw_mci_init_slot(). In that way you
will have clocks enabled+prepared and the runtime PM state reflects
that.

Later, when you might want to add clock (un)gating as a part of
runtime PM suspend/resume callbacks, you will need the above change
anyway.

> +
> host->biu_clk = devm_clk_get(host->dev, "biu");
> if (IS_ERR(host->biu_clk)) {
> dev_dbg(host->dev, "biu clock not available\n");
> @@ -2877,6 +2960,10 @@ int dw_mci_probe(struct dw_mci *host)
> if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO)
> dev_info(host->dev, "Internal DMAC interrupt fix enabled.\n");
>
> + /* no pm runtime wrappers in probe just to be consistent */
> + pm_runtime_mark_last_busy(host->dev);
> + pm_runtime_put_autosuspend(host->dev);

According the change suggested above, remove the "put".

> +
> return 0;
>
> err_dmaunmap:
> @@ -2891,6 +2978,9 @@ err_clk_biu:
> if (!IS_ERR(host->biu_clk))
> clk_disable_unprepare(host->biu_clk);
>
> + pm_runtime_put_sync(host->dev);

According the change suggested above, remove the "put".

> + pm_runtime_disable(host->dev);
> +
> return ret;
> }
> EXPORT_SYMBOL(dw_mci_probe);
> @@ -2899,6 +2989,8 @@ void dw_mci_remove(struct dw_mci *host)
> {
> int i;
>
> + pm_runtime_get_sync(host->dev);
> +
> mci_writel(host, RINTSTS, 0xFFFFFFFF);
> mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */
>
> @@ -2915,6 +3007,9 @@ void dw_mci_remove(struct dw_mci *host)
> if (host->use_dma && host->dma_ops->exit)
> host->dma_ops->exit(host);
>
> + pm_runtime_put_sync(host->dev);
> + pm_runtime_disable(host->dev);
> +

Change to:
pm_runtime_disable();
pm_runtime_put_noidle();

> if (!IS_ERR(host->ciu_clk))
> clk_disable_unprepare(host->ciu_clk);
>
> @@ -2937,11 +3032,13 @@ EXPORT_SYMBOL(dw_mci_suspend);
>
> int dw_mci_resume(struct dw_mci *host)
> {
> - int i, ret;
> + int i;
> +
> + dw_mci_pm_runtime_get(host);
>
> if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
> - ret = -ENODEV;
> - return ret;
> + dw_mci_pm_runtime_put(host);
> + return -ENODEV;
> }
>
> if (host->use_dma && host->dma_ops->init)
> @@ -2976,6 +3073,8 @@ int dw_mci_resume(struct dw_mci *host)
> /* Now that slots are all setup, we can enable card detect */
> dw_mci_enable_cd(host);
>
> + dw_mci_pm_runtime_put(host);
> +
> return 0;
> }
> EXPORT_SYMBOL(dw_mci_resume);
> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> index d239867..2317f4b7 100644
> --- a/drivers/mmc/host/dw_mmc.h
> +++ b/drivers/mmc/host/dw_mmc.h
> @@ -209,6 +209,8 @@ extern int dw_mci_suspend(struct dw_mci *host);
> extern int dw_mci_resume(struct dw_mci *host);
> #endif
>
> +#define DWMMC_AUTOSUSPEND_DELAY 50
> +
> /**
> * struct dw_mci_slot - MMC slot state
> * @mmc: The mmc_host representing this slot.
> --
> 1.7.9.5
>

Kind regards
Uffe
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