Re: [PATCH 01/20] net: phy: realtek: Fix events detection failure in LPI mode

From: Heiner Kallweit
Date: Sat Feb 20 2021 - 07:57:23 EST


On 20.02.2021 10:02, Serge Semin wrote:
> On Thu, Feb 11, 2021 at 10:39:41AM +0000, Russell King - ARM Linux admin wrote:
>> On Wed, Feb 10, 2021 at 07:47:20PM +0300, Serge Semin wrote:
>>> On Tue, Feb 09, 2021 at 10:56:46AM +0000, Russell King - ARM Linux admin wrote:
>>>> On Tue, Feb 09, 2021 at 11:37:29AM +0100, Heiner Kallweit wrote:
>>>>> Right, adding something like a genphy_{read,write}_mmd() doesn't make
>>>>> too much sense for now. What I meant is just exporting mmd_phy_indirect().
>>>>> Then you don't have to open-code the first three steps of a mmd read/write.
>>>>> And it requires no additional code in phylib.
>>>>
>>>> ... but at the cost that the compiler can no longer inline that code,
>>>> as I mentioned in my previous reply. (However, the cost of the accesses
>>>> will be higher.) On the plus side, less I-cache footprint, and smaller
>>>> kernel code.
>>>
>>> Just to note mmd_phy_indirect() isn't defined with inline specifier,
>>> but just as static and it's used twice in the
>>> drivers/net/phy/phy-core.c unit. So most likely the compiler won't
>>> inline the function code in there.
>>
>> You can't always tell whether the compiler will inline a static function
>> or not.
>
> Andrew, Heiner, Russell, what is your final decision about this? Shall
> we export the mmd_phy_indirect() method, implement new
> genphy_{read,write}_mmd() or just leave the patch as is manually
> accessing the MMD register in the driver?
>

If in doubt, leaving the patch as is would be fine with me.

> -Sergey
>
>>
>>> Anyway it's up to the PHY
>>> library maintainers to decide. Please settle the issue with Heiner and
>>> Andrew then. I am ok with both solutions and will do as you decide.
>>
>> FYI, *I* am one of the phylib maintainers.
>>
>> --
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