Patchwork mxc-nand: don't disable clock in mxcnd-suspend

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Submitter Uwe Kleine-König
Date Jan. 11, 2010, 4:53 p.m.
Message ID <1263228796-23054-1-git-send-email-u.kleine-koenig@pengutronix.de>
Download mbox | patch
Permalink /patch/42633/
State Accepted
Commit 9c14b153e6af1301f022d34f1f63888f333e3ef5
Headers show

Comments

Uwe Kleine-König - Jan. 11, 2010, 4:53 p.m.
The clock must already be off after mtd->suspend.  Disabling it again
results in an negative overflow of the clock usage count.  This didn't
hurt as mxcnd_resume undid it after wake up.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Vladimir Barinov <vova.barinov@gmail.com>
---
 drivers/mtd/nand/mxc_nand.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)
Sascha Hauer - Jan. 11, 2010, 6 p.m.
On Mon, Jan 11, 2010 at 05:53:16PM +0100, Uwe Kleine-König wrote:
> The clock must already be off after mtd->suspend.  Disabling it again
> results in an negative overflow of the clock usage count.  This didn't
> hurt as mxcnd_resume undid it after wake up.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Sascha Hauer <s.hauer@pengutronix.de>
> Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
> Cc: Vladimir Barinov <vova.barinov@gmail.com>

Acked-by: Sascha Hauer <s.hauer@pengutronix.de>

> ---
>  drivers/mtd/nand/mxc_nand.c |   10 ++++++----
>  1 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> index 84f3635..970ce6b 100644
> --- a/drivers/mtd/nand/mxc_nand.c
> +++ b/drivers/mtd/nand/mxc_nand.c
> @@ -888,8 +888,12 @@ static int mxcnd_suspend(struct platform_device *pdev, pm_message_t state)
>  	DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND : NAND suspend\n");
>  
>  	ret = mtd->suspend(mtd);
> -	/* Disable the NFC clock */
> -	clk_disable(host->clk);
> +
> +	/*
> +	 * nand_suspend locks the device for exclusive access, so
> +	 * the clock must already be off.
> +	 */
> +	BUG_ON(!ret && host->clk_act);
>  
>  	return ret;
>  }
> @@ -903,8 +907,6 @@ static int mxcnd_resume(struct platform_device *pdev)
>  
>  	DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND : NAND resume\n");
>  
> -	/* Enable the NFC clock */
> -	clk_enable(host->clk);
>  	mtd->resume(mtd);
>  
>  	return ret;
> -- 
> 1.6.5.2
> 
>

Patch

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index 84f3635..970ce6b 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -888,8 +888,12 @@  static int mxcnd_suspend(struct platform_device *pdev, pm_message_t state)
 	DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND : NAND suspend\n");
 
 	ret = mtd->suspend(mtd);
-	/* Disable the NFC clock */
-	clk_disable(host->clk);
+
+	/*
+	 * nand_suspend locks the device for exclusive access, so
+	 * the clock must already be off.
+	 */
+	BUG_ON(!ret && host->clk_act);
 
 	return ret;
 }
@@ -903,8 +907,6 @@  static int mxcnd_resume(struct platform_device *pdev)
 
 	DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND : NAND resume\n");
 
-	/* Enable the NFC clock */
-	clk_enable(host->clk);
 	mtd->resume(mtd);
 
 	return ret;