Re: [PATCH 2/5 v4] mmc: sh_mmcif: fix clock management

[Simon Horman <horms@verge.net.au>]

Hi Guennadi,

On Wed, Jun 13, 2012 at 03:37:19PM +0200, Guennadi Liakhovetski wrote:
> Regardless, whether the MMC bus clock is the same, as the PM clock on this
> specific interface, it has to be managed separately. Its proper management
> should also include enabling and disabling of the clock, whenever the
> interface is becoming active or going idle respectively.
> 
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> ---
>  drivers/mmc/host/sh_mmcif.c |   46 +++++++++++++++++++++---------------------
>  1 files changed, 23 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
> index d6ffb05..6a93b04 100644
> --- a/drivers/mmc/host/sh_mmcif.c
> +++ b/drivers/mmc/host/sh_mmcif.c
> @@ -942,6 +942,7 @@ static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  		}
>  		if (host->power) {
>  			pm_runtime_put(&host->pd->dev);
> +			clk_disable(host->hclk);
>  			host->power = false;
>  			if (p->down_pwr && ios->power_mode == MMC_POWER_OFF)
>  				p->down_pwr(host->pd);
> @@ -954,6 +955,7 @@ static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  		if (!host->power) {
>  			if (p->set_pwr)
>  				p->set_pwr(host->pd, ios->power_mode);
> +			clk_enable(host->hclk);
>  			pm_runtime_get_sync(&host->pd->dev);
>  			host->power = true;
>  			sh_mmcif_sync_reset(host);
> @@ -1278,22 +1280,11 @@ static int __devinit sh_mmcif_probe(struct platform_device *pdev)
>  	host->addr	= reg;
>  	host->timeout	= 1000;
>  
> -	snprintf(clk_name, sizeof(clk_name), "mmc%d", pdev->id);
> -	host->hclk = clk_get(&pdev->dev, clk_name);
> -	if (IS_ERR(host->hclk)) {
> -		dev_err(&pdev->dev, "cannot get clock \"%s\"\n", clk_name);
> -		ret = PTR_ERR(host->hclk);
> -		goto eclkget;
> -	}
> -	clk_enable(host->hclk);
> -	host->clk = clk_get_rate(host->hclk);
>  	host->pd = pdev;
>  
>  	spin_lock_init(&host->lock);
>  
>  	mmc->ops = &sh_mmcif_ops;
> -	mmc->f_max = host->clk / 2;
> -	mmc->f_min = host->clk / 512;
>  	if (pd->ocr)
>  		mmc->ocr_avail = pd->ocr;
>  	mmc->caps = MMC_CAP_MMC_HIGHSPEED;
> @@ -1305,18 +1296,30 @@ static int __devinit sh_mmcif_probe(struct platform_device *pdev)
>  	mmc->max_blk_count = mmc->max_req_size / mmc->max_blk_size;
>  	mmc->max_seg_size = mmc->max_req_size;
>  
> -	sh_mmcif_sync_reset(host);
>  	platform_set_drvdata(pdev, host);
>  
>  	pm_runtime_enable(&pdev->dev);
>  	host->power = false;
>  
> +	snprintf(clk_name, sizeof(clk_name), "mmc%d", pdev->id);
> +	host->hclk = clk_get(&pdev->dev, clk_name);
> +	if (IS_ERR(host->hclk)) {
> +		ret = PTR_ERR(host->hclk);
> +		dev_err(&pdev->dev, "cannot get clock \"%s\": %d\n", clk_name, ret);
> +		goto eclkget;
> +	}
> +	clk_enable(host->hclk);
> +	host->clk = clk_get_rate(host->hclk);
> +	mmc->f_max = host->clk / 2;
> +	mmc->f_min = host->clk / 512;
> +
>  	ret = pm_runtime_resume(&pdev->dev);
>  	if (ret < 0)
>  		goto eresume;
>  
>  	INIT_DELAYED_WORK(&host->timeout_work, mmcif_timeout_work);
>  
> +	sh_mmcif_sync_reset(host);
>  	sh_mmcif_writel(host->addr, MMCIF_CE_INT_MASK, MASK_ALL);
>  
>  	ret = request_threaded_irq(irq[0], sh_mmcif_intr, sh_mmcif_irqt, 0, "sh_mmc:error", host);
> @@ -1330,6 +1333,7 @@ static int __devinit sh_mmcif_probe(struct platform_device *pdev)
>  		goto ereqirq1;
>  	}
>  
> +	clk_disable(host->hclk);
>  	ret = mmc_add_host(mmc);
>  	if (ret < 0)
>  		goto emmcaddh;

Could you clarify the purpose of two hunks above.
They seem to move code down in sh_mmcif_probe().
Is this related to the call to pm_runtime_enable() ?

> @@ -1348,9 +1352,10 @@ ereqirq1:
>  ereqirq0:
>  	pm_runtime_suspend(&pdev->dev);
>  eresume:
> -	pm_runtime_disable(&pdev->dev);
>  	clk_disable(host->hclk);
> +	clk_put(host->hclk);
>  eclkget:
> +	pm_runtime_disable(&pdev->dev);
>  	mmc_free_host(mmc);
>  ealloch:
>  	iounmap(reg);
> @@ -1363,6 +1368,7 @@ static int __devexit sh_mmcif_remove(struct platform_device *pdev)
>  	int irq[2];
>  
>  	host->dying = true;
> +	clk_enable(host->hclk);
>  	pm_runtime_get_sync(&pdev->dev);
>  
>  	dev_pm_qos_hide_latency_limit(&pdev->dev);
> @@ -1388,9 +1394,9 @@ static int __devexit sh_mmcif_remove(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, NULL);
>  
> -	clk_disable(host->hclk);
>  	mmc_free_host(host->mmc);
>  	pm_runtime_put_sync(&pdev->dev);
> +	clk_disable(host->hclk);
>  	pm_runtime_disable(&pdev->dev);
>  
>  	return 0;
> @@ -1399,24 +1405,18 @@ static int __devexit sh_mmcif_remove(struct platform_device *pdev)
>  #ifdef CONFIG_PM
>  static int sh_mmcif_suspend(struct device *dev)
>  {
> -	struct platform_device *pdev = to_platform_device(dev);
> -	struct sh_mmcif_host *host = platform_get_drvdata(pdev);
> +	struct sh_mmcif_host *host = dev_get_drvdata(dev);
>  	int ret = mmc_suspend_host(host->mmc);
>  
> -	if (!ret) {
> +	if (!ret)
>  		sh_mmcif_writel(host->addr, MMCIF_CE_INT_MASK, MASK_ALL);
> -		clk_disable(host->hclk);
> -	}
>  
>  	return ret;
>  }
>  
>  static int sh_mmcif_resume(struct device *dev)
>  {
> -	struct platform_device *pdev = to_platform_device(dev);
> -	struct sh_mmcif_host *host = platform_get_drvdata(pdev);
> -
> -	clk_enable(host->hclk);
> +	struct sh_mmcif_host *host = dev_get_drvdata(dev);
>  
>  	return mmc_resume_host(host->mmc);
>  }
> -- 
> 1.7.2.5
> 
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