Re: [PATCH] net/at91_ether: prepare and unprepare clock

[Boris Brezillon]

On Wed,  7 Jan 2015 23:59:26 +0100
Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx> wrote:

> The clock is enabled without being prepared, this leads to:
> 
> WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:889 __clk_enable+0x24/0xa8()
> 
> and a non working ethernet interface.
> 
> Use clk_prepare_enable() and clk_disable_unprepare() to handle the clock.
> 
> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>

Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>

> ---
>  drivers/net/ethernet/cadence/at91_ether.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/cadence/at91_ether.c b/drivers/net/ethernet/cadence/at91_ether.c
> index 55eb7f2af2b4..7ef55f5fa664 100644
> --- a/drivers/net/ethernet/cadence/at91_ether.c
> +++ b/drivers/net/ethernet/cadence/at91_ether.c
> @@ -340,7 +340,7 @@ static int __init at91ether_probe(struct platform_device *pdev)
>  		res = PTR_ERR(lp->pclk);
>  		goto err_free_dev;
>  	}
> -	clk_enable(lp->pclk);
> +	clk_prepare_enable(lp->pclk);
>  
>  	lp->hclk = ERR_PTR(-ENOENT);
>  	lp->tx_clk = ERR_PTR(-ENOENT);
> @@ -406,7 +406,7 @@ static int __init at91ether_probe(struct platform_device *pdev)
>  err_out_unregister_netdev:
>  	unregister_netdev(dev);
>  err_disable_clock:
> -	clk_disable(lp->pclk);
> +	clk_disable_unprepare(lp->pclk);
>  err_free_dev:
>  	free_netdev(dev);
>  	return res;
> @@ -424,7 +424,7 @@ static int at91ether_remove(struct platform_device *pdev)
>  	kfree(lp->mii_bus->irq);
>  	mdiobus_free(lp->mii_bus);
>  	unregister_netdev(dev);
> -	clk_disable(lp->pclk);
> +	clk_disable_unprepare(lp->pclk);
>  	free_netdev(dev);
>  
>  	return 0;
> @@ -440,7 +440,7 @@ static int at91ether_suspend(struct platform_device *pdev, pm_message_t mesg)
>  		netif_stop_queue(net_dev);
>  		netif_device_detach(net_dev);
>  
> -		clk_disable(lp->pclk);
> +		clk_disable_unprepare(lp->pclk);
>  	}
>  	return 0;
>  }
> @@ -451,7 +451,7 @@ static int at91ether_resume(struct platform_device *pdev)
>  	struct macb *lp = netdev_priv(net_dev);
>  
>  	if (netif_running(net_dev)) {
> -		clk_enable(lp->pclk);
> +		clk_prepare_enable(lp->pclk);
>  
>  		netif_device_attach(net_dev);
>  		netif_start_queue(net_dev);



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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