Date:	Thu, 12 Mar 2015 11:08:51 +0900
From:	Jaehoon Chung <jh80.chung@...sung.com>
To:	Karol Wrona <k.wrona@...sung.com>,
	Seungwon Jeon <tgih.jun@...sung.com>,
	Jaehoon Chung <jh80.chung@...sung.com>,
	linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org,
	Ulf Hansson <ulf.hansson@...aro.org>
Cc:	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
	Kyungmin Park <kyungmin.park@...sung.com>,
	Karol Wrona <wrona.vy@...il.com>
Subject: Re: [PATCH v3 1/1] mmc: dw_mmc: Add runtime pm to dw_mmc

Hi, Karol.

Is there the benefit of power consumption? If there is, could you share the result?

On 03/09/2015 10:46 PM, Karol Wrona 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@...sung.com>
> Acked-by: Kyungmin Park <kyungmin.park@...sung.com>
> ---
>  drivers/mmc/host/dw_mmc.c |  103 ++++++++++++++++++++++++++++++++++++++++++---
>  drivers/mmc/host/dw_mmc.h |    2 +
>  2 files changed, 99 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 47dfd0e..4f45932 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"
>  
> @@ -113,6 +114,8 @@ static int dw_mci_req_show(struct seq_file *s, void *v)
>  	struct mmc_command *stop;
>  	struct mmc_data	*data;
>  
> +	pm_runtime_get_sync(slot->host->dev);
> +
>  	/* Make sure we get a consistent snapshot */
>  	spin_lock_bh(&slot->host->lock);
>  	mrq = slot->mrq;
> @@ -142,6 +145,9 @@ static int dw_mci_req_show(struct seq_file *s, void *v)
>  
>  	spin_unlock_bh(&slot->host->lock);
>  
> +	pm_runtime_mark_last_busy(slot->host->dev);
> +	pm_runtime_put_autosuspend(slot->host->dev);
> +

I suggest to use dw_mci_pm_runtime_get/put(). (refer to sdhci.c)

static int dw_mci_pm_rumtime_get(struct dw_mci *host)
{
	....
}

static int dw_mci_runtime_put(struct dw_mci *host)
{
	....
}


>  	return 0;
>  }
>  
> @@ -1071,6 +1077,8 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
>  
>  	WARN_ON(slot->mrq);
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	/*
>  	 * 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 +1090,9 @@ 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);
> +
> +		pm_runtime_mark_last_busy(host->dev);
> +		pm_runtime_put_autosuspend(host->dev);
>  		return;
>  	}
>  
> @@ -1109,6 +1120,8 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  		slot->ctype = SDMMC_CTYPE_1BIT;
>  	}
>  
> +	pm_runtime_get_sync(slot->host->dev);
> +
>  	regs = mci_readl(slot->host, UHS_REG);
>  
>  	/* DDR mode set */
> @@ -1139,7 +1152,7 @@ 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 _end;

why do you use underline? (goto _end -> goto out)

>  			}
>  		}
>  		set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
> @@ -1192,6 +1205,10 @@ 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;
> +
> +_end:
> +	pm_runtime_mark_last_busy(slot->host->dev);
> +	pm_runtime_put_autosuspend(slot->host->dev);
>  }
>  
>  static int dw_mci_card_busy(struct mmc_host *mmc)
> @@ -1199,12 +1216,17 @@ static int dw_mci_card_busy(struct mmc_host *mmc)
>  	struct dw_mci_slot *slot = mmc_priv(mmc);
>  	u32 status;
>  
> +	pm_runtime_get_sync(slot->host->dev);
> +
>  	/*
>  	 * Check the busy bit which is low when DAT[3:0]
>  	 * (the data lines) are 0000
>  	 */
>  	status = mci_readl(slot->host, STATUS);
>  
> +	pm_runtime_mark_last_busy(slot->host->dev);
> +	pm_runtime_put_autosuspend(slot->host->dev);
> +
>  	return !!(status & SDMMC_STATUS_BUSY);
>  }
>  
> @@ -1217,6 +1239,8 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
>  	int min_uv, max_uv;
>  	int ret;
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	/*
>  	 * Program the voltage.  Note that some instances of dw_mmc may use
>  	 * the UHS_REG for this.  For other instances (like exynos) the UHS_REG
> @@ -1239,11 +1263,17 @@ 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);
> +
> +			pm_runtime_mark_last_busy(host->dev);
> +			pm_runtime_put_autosuspend(host->dev);
>  			return ret;

use the "goto statement"? (goto out;)

Best Regards,
Jaehoon Chung

>  		}
>  	}
>  	mci_writel(host, UHS_REG, uhs);
>  
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return 0;
>  }
>  
> @@ -1253,6 +1283,8 @@ 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);
>  
> +	pm_runtime_get_sync(slot->host->dev);
> +
>  	/* 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 +1295,9 @@ static int dw_mci_get_ro(struct mmc_host *mmc)
>  		read_only =
>  			mci_readl(slot->host, WRTPRT) & (1 << slot->id) ? 1 : 0;
>  
> +	pm_runtime_mark_last_busy(slot->host->dev);
> +	pm_runtime_put_autosuspend(slot->host->dev);
> +
>  	dev_dbg(&mmc->class_dev, "card is %s\n",
>  		read_only ? "read-only" : "read-write");
>  
> @@ -1277,6 +1312,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
>  	struct dw_mci *host = slot->host;
>  	int gpio_cd = mmc_gpio_get_cd(mmc);
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	/* Use platform get_cd function, else try onboard card detect */
>  	if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
>  		present = 1;
> @@ -1296,6 +1333,9 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
>  	}
>  	spin_unlock_bh(&host->lock);
>  
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return present;
>  }
>  
> @@ -1304,6 +1344,8 @@ 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;
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	/*
>  	 * 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 +1373,9 @@ static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
>  				     SDMMC_CMD_PRV_DAT_WAIT, 0);
>  		}
>  	}
> +
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
>  }
>  
>  static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
> @@ -1340,6 +1385,9 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
>  	unsigned long irqflags;
>  	u32 int_mask;
>  
> +	if (enb)
> +		pm_runtime_get_sync(slot->host->dev);
> +
>  	spin_lock_irqsave(&host->irq_lock, irqflags);
>  
>  	/* Enable/disable Slot Specific SDIO interrupt */
> @@ -1351,6 +1399,12 @@ 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) {
> +		pm_runtime_mark_last_busy(slot->host->dev);
> +		pm_runtime_put_autosuspend(slot->host->dev);
> +	}
>  }
>  
>  static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> @@ -1360,8 +1414,14 @@ 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;
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	if (drv_data && drv_data->execute_tuning)
>  		err = drv_data->execute_tuning(slot);
> +
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return err;
>  }
>  
> @@ -1371,9 +1431,14 @@ 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;
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	if (drv_data && drv_data->prepare_hs400_tuning)
>  		return drv_data->prepare_hs400_tuning(host, ios);
>  
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return 0;
>  }
>  
> @@ -1414,10 +1479,14 @@ 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 {
> +			pm_runtime_mark_last_busy(host->dev);
> +			pm_runtime_put_autosuspend(host->dev);
> +
>  			host->state = STATE_IDLE;
> +		}
>  	}
>  
>  	spin_unlock(&host->lock);
> @@ -2688,6 +2757,11 @@ 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);
> +
>  	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 +2951,9 @@ 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");
>  
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return 0;
>  
>  err_dmaunmap:
> @@ -2891,6 +2968,9 @@ err_clk_biu:
>  	if (!IS_ERR(host->biu_clk))
>  		clk_disable_unprepare(host->biu_clk);
>  
> +	pm_runtime_put_sync(host->dev);
> +	pm_runtime_disable(host->dev);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL(dw_mci_probe);
> @@ -2899,6 +2979,8 @@ 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 +2997,9 @@ 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);
> +
>  	if (!IS_ERR(host->ciu_clk))
>  		clk_disable_unprepare(host->ciu_clk);
>  
> @@ -2937,11 +3022,14 @@ EXPORT_SYMBOL(dw_mci_suspend);
>  
>  int dw_mci_resume(struct dw_mci *host)
>  {
> -	int i, ret;
> +	int i;
> +
> +	pm_runtime_get_sync(host->dev);
>  
>  	if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
> -		ret = -ENODEV;
> -		return ret;
> +		pm_runtime_mark_last_busy(host->dev);
> +		pm_runtime_put_autosuspend(host->dev);
> +		return -ENODEV;
>  	}
>  
>  	if (host->use_dma && host->dma_ops->init)
> @@ -2976,6 +3064,9 @@ int dw_mci_resume(struct dw_mci *host)
>  	/* Now that slots are all setup, we can enable card detect */
>  	dw_mci_enable_cd(host);
>  
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	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.
> 

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