On 22-10-2018 18:13, Florian Fainelli wrote:
> On 10/22/18 8:48 AM, Russell King - ARM Linux wrote:
>> On Mon, Oct 22, 2018 at 01:47:48PM +0100, Jose Abreu wrote:
>>> Hello,
>>>
>>> On 22-10-2018 13:28, Andrew Lunn wrote:
>>>>> EXPORT_SYMBOL_GPL(gen10g_resume);
>>>>> @@ -327,7 +381,7 @@ struct phy_driver genphy_10g_driver = {
>>>>> .phy_id = 0xffffffff,
>>>>> .phy_id_mask = 0xffffffff,
>>>>> .name = "Generic 10G PHY",
>>>>> - .soft_reset = gen10g_no_soft_reset,
>>>>> + .soft_reset = gen10g_soft_reset,
>>>>> .config_init = gen10g_config_init,
>>>>> .features = 0,
>>>>> .aneg_done = genphy_c45_aneg_done,
>>>> Hi Jose
>>>>
>>>> You need to be careful here. There is a reason this is called
>>>> gen10g_no_soft_reset, rather than having an empty
>>>> gen10g_soft_reset. Some PHYs break when you do a reset. So adding a
>>>> gen10g_soft_reset is fine, but don't change this here, without first
>>>> understanding the history, and talking to Russell King.
>>> Hmm, the reset function only interacts with standard PCS
>>> registers, which should always be available ...
>>>
>>> >From my tests I need to do at least 1 reset during power-up so in
>>> ultimate case I can add a feature quirk or similar.
>>>
>>> Russell, can you please comment ?
>> Setting the reset bit on 88x3310 causes the entire device to become
>> completely inaccessible until hardware reset. Therefore, this bit
>> must _never_ be set for these devices. That said, we have a separate
>> driver for these PHYs, but that will only be used for them if it's
>> present in the kernel. If we accidentally fall back to the generic
>> driver, then we'll screw the 88x3310 until a full hardware reset.
>>
>> We also have a bunch of net devices that make use of this crippled
>> "generic" 10G support - we don't know whether resetting the PHY
>> for those systems will cause a regression - maybe board firmware
>> already configured the PHY? I can't say either way on that, except
>> that we've had crippled 10G support in PHYLIB for a number of years
>> now _with_ users, and adding reset support drastically changes the
>> subsystem's behaviour for these users.
>>
>> I would recommend not touching the generic 10G driver, but instead
>> implement your own driver for your PHY to avoid causing regressions.
>>
> Agreed.
What about .suspend / .resume ?
Thanks and Best Regards,
Jose Miguel Abreu
