Why /sys/class/net/*/features is read-only?

Why /sys/class/net/*/features is read-only?

[Catalin(ux aka Dino) BOIE]

Hello!

Why features file is read-only. If an admin want to force some attributes, 
we can let them, right?

This way, an admin can force SG and HW_CSUM on a bridge, for example. ;)

I can make a patch, if you want.

Thank you!
---
Catalin(ux aka Dino) BOIE
catab at deuroconsult.ro
http://kernel.umbrella.ro/

Re: Why /sys/class/net/*/features is read-only?

[Stephen Hemminger]

On Mon, 23 May 2005 10:46:50 +0300 (EEST)
"Catalin(ux aka Dino) BOIE" <util@deuroconsult.ro> wrote:

> Hello!
> 
> Why features file is read-only. If an admin want to force some attributes, 
> we can let them, right?
>

Leave it read-only because the hardware may not want to allow them on that flavor and so it would
have to be device specific.

Re: Why /sys/class/net/*/features is read-only?

[Catalin(ux aka Dino) BOIE]

On Mon, 23 May 2005, Stephen Hemminger wrote:

> On Mon, 23 May 2005 10:46:50 +0300 (EEST)
> "Catalin(ux aka Dino) BOIE" <util@deuroconsult.ro> wrote:
>
>> Hello!
>>
>> Why features file is read-only. If an admin want to force some attributes,
>> we can let them, right?
>>
>
> Leave it read-only because the hardware may not want to allow them on that flavor and so it would
> have to be device specific.

You are clear right for hardware devices, but for software ones (bridge 
for example) it makes sense. Anyway, only admin can change them.

If you have a bridge with 5 net cards and 4 supports SG, some people 
may want to force SG on the bridge.

---
Catalin(ux aka Dino) BOIE
catab at deuroconsult.ro
http://kernel.umbrella.ro/

Re: Why /sys/class/net/*/features is read-only?

[David S. Miller]

From: "Catalin(ux aka Dino) BOIE" <util@deuroconsult.ro>
Date: Mon, 23 May 2005 23:49:57 +0300 (EEST)

> If you have a bridge with 5 net cards and 4 supports SG, some people 
> may want to force SG on the bridge.

Let them use ethtool :-)

Re: Why /sys/class/net/*/features is read-only?

[Stephen Hemminger]

On Mon, 23 May 2005 23:49:57 +0300 (EEST)
"Catalin(ux aka Dino) BOIE" <util@deuroconsult.ro> wrote:

> On Mon, 23 May 2005, Stephen Hemminger wrote:
> 
> > On Mon, 23 May 2005 10:46:50 +0300 (EEST)
> > "Catalin(ux aka Dino) BOIE" <util@deuroconsult.ro> wrote:
> >
> >> Hello!
> >>
> >> Why features file is read-only. If an admin want to force some attributes,
> >> we can let them, right?
> >>
> >
> > Leave it read-only because the hardware may not want to allow them on that flavor and so it would
> > have to be device specific.
> 
> You are clear right for hardware devices, but for software ones (bridge 
> for example) it makes sense. Anyway, only admin can change them.
> 
> If you have a bridge with 5 net cards and 4 supports SG, some people 
> may want to force SG on the bridge.

Then implement ethtool on the bridge device, it wouldn't be hard to do that.

Re: Why /sys/class/net/*/features is read-only?

[Catalin(ux aka Dino) BOIE]

On Mon, 23 May 2005, David S. Miller wrote:

> From: "Catalin(ux aka Dino) BOIE" <util@deuroconsult.ro>
> Date: Mon, 23 May 2005 23:49:57 +0300 (EEST)
>
>> If you have a bridge with 5 net cards and 4 supports SG, some people
>> may want to force SG on the bridge.
>
> Let them use ethtool :-)

They can't on a bridge device, right?

---
Catalin(ux aka Dino) BOIE
catab at deuroconsult.ro
http://kernel.umbrella.ro/

Re: Why /sys/class/net/*/features is read-only?

[David S. Miller]

From: "Catalin(ux aka Dino) BOIE" <util@deuroconsult.ro>
Date: Tue, 24 May 2005 00:33:14 +0300 (EEST)

> On Mon, 23 May 2005, David S. Miller wrote:
> 
> > Let them use ethtool :-)
> 
> They can't on a bridge device, right?

Currently no.  But there is no reason the bridge device
should not have ethtool support added to it, and that's
where this functionality belongs.

Re: Why /sys/class/net/*/features is read-only?

[Catalin(ux aka Dino) BOIE]

On Mon, 23 May 2005, David S. Miller wrote:

> From: "Catalin(ux aka Dino) BOIE" <util@deuroconsult.ro>
> Date: Tue, 24 May 2005 00:33:14 +0300 (EEST)
>
>> On Mon, 23 May 2005, David S. Miller wrote:
>>
>>> Let them use ethtool :-)
>>
>> They can't on a bridge device, right?
>
> Currently no.  But there is no reason the bridge device
> should not have ethtool support added to it, and that's
> where this functionality belongs.

OK. I made this patch only to test how well slave notification worked.
Next days I will implement ethtool for bridge.

Thank you!
---
Catalin(ux aka Dino) BOIE
catab at deuroconsult.ro
http://kernel.umbrella.ro/