Subject: Re: [RFC 02/11] net: phy: Simplify MMD device list termination

From: Jeremy Linton <[email-masked]>
Date: Sun, 24 May 2020 21:48:55 -0500

Hi,

On 5/23/20 1:36 PM, Russell King - ARM Linux admin wrote:
> On Fri, May 22, 2020 at 04:30:50PM -0500, Jeremy Linton wrote:
>> Since we are already checking for *devs == 0 after
>> the loop terminates, we can add a mostly F's check
>> as well. With that change we can simplify the return/break
>> sequence inside the loop.
>>
>> Add a valid_phy_id() macro for this, since we will be using it
>> in a couple other places.
> 
> I'm not sure you have the name of this correct, and your usage layer
> in your patch series is correct.

Or the name is poor..

> 
>>
>> Signed-off-by: Jeremy Linton <[email-masked]>
>> ---
>>   drivers/net/phy/phy_device.c | 15 +++++++--------
>>   1 file changed, 7 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
>> index 245899b58a7d..7746c07b97fe 100644
>> --- a/drivers/net/phy/phy_device.c
>> +++ b/drivers/net/phy/phy_device.c
>> @@ -695,6 +695,11 @@ static int get_phy_c45_devs_in_pkg(struct mii_bus *bus, int addr, int dev_addr,
>>   	return 0;
>>   }
>>   
>> +static bool valid_phy_id(int val)
>> +{
>> +	return (val > 0 && ((val & 0x1fffffff) != 0x1fffffff));
>> +}
>> +
>>   /**
>>    * get_phy_c45_ids - reads the specified addr for its 802.3-c45 IDs.
>>    * @bus: the target MII bus
>> @@ -732,18 +737,12 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
>>   			phy_reg = get_phy_c45_devs_in_pkg(bus, addr, 0, devs);
>>   			if (phy_reg < 0)
>>   				return -EIO;
>> -			/* no device there, let's get out of here */
>> -			if ((*devs & 0x1fffffff) == 0x1fffffff) {
>> -				*phy_id = 0xffffffff;
>> -				return 0;
>> -			} else {
>> -				break;
>> -			}
>> +			break;
>>   		}
>>   	}
>>   
>>   	/* no reported devices */
>> -	if (*devs == 0) {
>> +	if (!valid_phy_id(*devs)) {
> 
> You are using this to validate the "devices in package" value, not the
> PHY ID value.  So, IMHO this should be called "valid_devs_in_package()"
> or similar.

Hmmm, its more "valid_phy_reg()" since it ends up being used to validate 
both the devs in package as well as phy id.

>>   		*phy_id = 0xffffffff;
>>   		return 0;
>>   	}
>> -- 
>> 2.26.2