Re: [dpdk-dev] [PATCH v3 1/2] net/ixgbe: fix x550 code to handle unidentified PHY

[Chas Williams <3chas3@gmail.com>]

On 11/05/2018 12:41 PM, Zhang, Qi Z wrote:
> 
> 
>> -----Original Message-----
>> From: Luca Boccassi [mailto:bluca@debian.org]
>> Sent: Friday, November 2, 2018 8:19 AM
>> To: dev@dpdk.org
>> Cc: Lu, Wenzhuo <wenzhuo.lu@intel.com>; Ananyev, Konstantin
>> <konstantin.ananyev@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>;
>> 3chas3@gmail.com; Luca Boccassi <bluca@debian.org>; stable@dpdk.org
>> Subject: [PATCH v3 1/2] net/ixgbe: fix x550 code to handle unidentified PHY
>>
>> ixgbe_identify_sfp_module_X550em() was missing the code to handle
>> unidentified PHY that has been there in 82599 so it was not able to complete
>> initialization of ixgbe sequence if no sfp plugged in.
>> Port it over to return an appropriate type and complete init sequence
>> properly.
>>
>> Fixes: d2e72774e58c ("ixgbe/base: support X550")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Luca Boccassi <bluca@debian.org>
>> ---
>> v2: refresh to remove merge conflict with master
>> v3: coalesce fix into ixgbe_identify_sfp_module_X550em to avoid
>>      code duplication, improve comment
>>
>>   drivers/net/ixgbe/base/ixgbe_x550.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/net/ixgbe/base/ixgbe_x550.c
>> b/drivers/net/ixgbe/base/ixgbe_x550.c
>> index f7b98af52..a88d5c86a 100644
>> --- a/drivers/net/ixgbe/base/ixgbe_x550.c
>> +++ b/drivers/net/ixgbe/base/ixgbe_x550.c
>> @@ -1561,6 +1561,12 @@ s32 ixgbe_identify_sfp_module_X550em(struct
>> ixgbe_hw *hw)
>>
>>   	status = ixgbe_identify_module_generic(hw);
>>
>> +	/* Set PHY type none if no PHY detected to allow init without SFP */
>> +	if (hw->phy.type == ixgbe_phy_unknown) {
>> +		hw->phy.type = ixgbe_phy_none;
> 
> Set PHY type to none for a device that does have PHY looks weird.
> does ixgeb_phy_generic works here?

Yes, it does seem strange but that's what ixgbe_identify_sfp_module_generic
seems to do:

	err_read_i2c_eeprom:
		hw->phy.sfp_type = ixgbe_sfp_type_not_present;
		if (hw->phy.type != ixgbe_phy_nl) {
			hw->phy.id = 0;
			hw->phy.type = ixgbe_phy_unknown;
		}

The QSFP version a little more forceful:

	err_read_i2c_eeprom:
		hw->phy.sfp_type = ixgbe_sfp_type_not_present;
		hw->phy.id = 0;
		hw->phy.type = ixgbe_phy_unknown;

If we go forward without setting the phy_type to none, we will eventually
run into issues calling other phy routines.

So should a lack of SFP, reset the PHY type? It's hazy because the 
difference
between PHY and SFP isn't that clear to me here.

> Where is failure you met with ixgbe_phy_unknown?
> 
>> +		return IXGBE_SUCCESS;
>> +	}
>> +
>>   	if (status != IXGBE_SUCCESS)
>>   		return status;
>>
>> --
>> 2.19.1
>