netdev - Re: [PATCH V2] net: phy: tja11xx: Add IRQ support to the driver

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Message-ID: <7b280744-9d23-4780-0852-aa502768837f@denx.de>
Date:   Mon, 17 Jun 2019 19:43:33 +0200
From:   Marek Vasut <marex@...x.de>
To:     Andrew Lunn <andrew@...n.ch>
Cc:     Heiner Kallweit <hkallweit1@...il.com>, netdev@...r.kernel.org,
        Florian Fainelli <f.fainelli@...il.com>,
        Guenter Roeck <linux@...ck-us.net>,
        Jean Delvare <jdelvare@...e.com>, linux-hwmon@...r.kernel.org
Subject: Re: [PATCH V2] net: phy: tja11xx: Add IRQ support to the driver

On 6/17/19 7:16 PM, Andrew Lunn wrote:
> On Thu, Jun 13, 2019 at 05:42:53PM +0200, Marek Vasut wrote:
>> On 5/30/19 1:46 AM, Marek Vasut wrote:
>>> On 5/30/19 1:29 AM, Andrew Lunn wrote:
>>>> On Tue, May 28, 2019 at 11:33:33PM +0200, Marek Vasut wrote:
>>>>> On 5/28/19 11:22 PM, Andrew Lunn wrote:
>>>>>>> The link detection on the TJA1100 (not TJA1101) seems unstable at best,
>>>>>>> so I better use all the interrupt sources to nudge the PHY subsystem and
>>>>>>> have it check the link change.
>>>>>>
>>>>>> Then it sounds like you should just ignore interrupts and stay will
>>>>>> polling for the TJA1100.
>>>>>
>>>>> Polling for the link status change is slow(er) than the IRQ driven
>>>>> operation, so I would much rather use the interrupts.
>>>>
>>>> I agree about the speed, but it seems like interrupts on this PHY are
>>>> not so reliable. Polling always works. But unfortunately, you cannot
>>>> have both interrupts and polling to fix up problems when interrupts
>>>> fail. Your call, do you think interrupts really do work?
>>>
>>> It works fine for me this way. And mind you, it's only the TJA1100
>>> that's flaky, the TJA1101 is better.
>>>
>>>> If you say that tja1101 works as expected, then please just use the
>>>> link up/down bits for it.
>>>
>>> I still don't know which bits really trigger link status changes, so I'd
>>> like to play it safe and just trigger on all of them.
>>
>> So what do we do here ?
> 
> Hi Marek
> 
> My personal preference would be to just enable what is needed. But
> I won't block a patch which enables everything.

Thanks. I don't know exactly what is needed , but I know that if I
enable everything, it works fine. And I'm not getting an interrupt storm
either, so it's probably OKish.

-- 
Best regards,
Marek Vasut