Subject: Re: [PATCH 1/2] net: davinci_mdio: enable and disable clock

From: Daniel Mack <[email-masked]>
Date: Fri, 03 Aug 2012 07:22:40 +0200

On 03.08.2012 07:16, Vaibhav Hiremath wrote:
> 
> 
> On 8/3/2012 1:13 AM, Daniel Mack wrote:
>> Make the driver control the device clocks. Appearantly, the Davinci
>> platform probes this driver with the clock all powered up, but on OMAP,
>> this isn't the case.
>>
>> Signed-off-by: Daniel Mack <[email-masked]>
>> ---
>>  drivers/net/ethernet/ti/davinci_mdio.c | 16 ++++++++++++++--
>>  1 file changed, 14 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
>> index cd7ee20..b4b6015 100644
>> --- a/drivers/net/ethernet/ti/davinci_mdio.c
>> +++ b/drivers/net/ethernet/ti/davinci_mdio.c
>> @@ -332,6 +332,8 @@ static int __devinit davinci_mdio_probe(struct platform_device *pdev)
>>  		goto bail_out;
>>  	}
>>  
>> +	clk_enable(data->clk);
>> +
>>  	dev_set_drvdata(dev, data);
>>  	data->dev = dev;
>>  	spin_lock_init(&data->lock);
>> @@ -379,8 +381,11 @@ bail_out:
>>  	if (data->bus)
>>  		mdiobus_free(data->bus);
>>  
>> -	if (data->clk)
>> +	if (data->clk) {
>> +		clk_disable(data->clk);
>>  		clk_put(data->clk);
>> +	}
>> +
>>  	pm_runtime_put_sync(&pdev->dev);
>>  	pm_runtime_disable(&pdev->dev);
>>  
>> @@ -397,8 +402,11 @@ static int __devexit davinci_mdio_remove(struct platform_device *pdev)
>>  	if (data->bus)
>>  		mdiobus_free(data->bus);
>>  
>> -	if (data->clk)
>> +	if (data->clk) {
>> +		clk_disable(data->clk);
>>  		clk_put(data->clk);
>> +	}
>> +
>>  	pm_runtime_put_sync(&pdev->dev);
>>  	pm_runtime_disable(&pdev->dev);
>>  
>> @@ -427,6 +435,8 @@ static int davinci_mdio_suspend(struct device *dev)
>>  	data->suspended = true;
>>  	spin_unlock(&data->lock);
>>  
>> +	clk_disable(data->clk);
>> +
>>  	return 0;
>>  }
>>  
>> @@ -435,6 +445,8 @@ static int davinci_mdio_resume(struct device *dev)
>>  	struct davinci_mdio_data *data = dev_get_drvdata(dev);
>>  	u32 ctrl;
>>  
>> +	clk_enable(data->clk);
>> +
> 
> Danial,
> 
> I would request you to wait for this, its not that simple and straight.
> And once you migrate to runtime PM you don't need clk_enable/disable,
> this should get handled under runtime PM api's.

As I said, it can be dropped.

> Also have you read my another email post -
> 
> http://comments.gmane.org/gmane.linux.ports.arm.omap/80796
> 
> Certainly, with respect to CPSW & MDIO, this patch is not enough and
> requires further investigation. I have started looking at this and
> hopefully will have some solution soon...

Ok, no problem. We certainly need the DT bindings for davinci_mdio. With
that applied, and the hwmod added (in the patch I posted yesterday), I
can at least mount the rootfs via NFS, which is all I currently need.

Best regards,
Daniel