Re: [PATCH net-next] pcnet32: remove VLB support

Re: [PATCH net-next] pcnet32: remove VLB support

[Maciej W. Rozycki]

[+cc Thomas, linux-mips]

On Fri, 9 Jan 2026, Simon Horman wrote:

> > This allows the code managing device instances to be simplified
> > significantly. The VLB bus is very obsolete and last appeared on
> > P5 Pentium-era hardware. Support for it has been removed from
> > other drivers, and it is highly unlikely anyone is using it with
> > modern Linux kernels.
> > 
> > Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
> 
> Hi Ethan,
> 
> I don't think this driver has received much attention for some time.
> So, unless you have hardware to test changes on, I would suggest
> either leaving it alone or, if we suspect there are no users,
> removing it.

 You mean discarding the whole of drivers/net/ethernet/amd/pcnet32.c?  If 
so, then it's a hard NAK from me.  It's the onboard/netboot interface of 
the MIPS Malta platform and it continues being used regularly, primarily 
with QEMU setups, although I have actual Malta hardware in my lab too, 
usually running 24/7.  It's one of the primary MIPS plaforms, cf. 
arch/mips/configs/malta_defconfig.

 No attention means the driver just works, why wouldn't it?  It's no 
rocket science.  FWIW I continue using several drivers that saw little to 
no change recently across various platforms.

 As to VLB support, I guess nobody cares nowadays.  I used to have such a 
system, but haven't seen one in some three decades now and never used this 
driver with one.

  Maciej

Re: [PATCH net-next] pcnet32: remove VLB support

[Thomas Bogendoerfer]

On Sun, Jan 11, 2026 at 12:40:56AM +0000, Maciej W. Rozycki wrote:
> [+cc Thomas, linux-mips]
> 
> On Fri, 9 Jan 2026, Simon Horman wrote:
> 
> > > This allows the code managing device instances to be simplified
> > > significantly. The VLB bus is very obsolete and last appeared on
> > > P5 Pentium-era hardware. Support for it has been removed from
> > > other drivers, and it is highly unlikely anyone is using it with
> > > modern Linux kernels.
> > > 
> > > Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
> > 
> > Hi Ethan,
> > 
> > I don't think this driver has received much attention for some time.
> > So, unless you have hardware to test changes on, I would suggest
> > either leaving it alone or, if we suspect there are no users,
> > removing it.
> 
>  You mean discarding the whole of drivers/net/ethernet/amd/pcnet32.c?  If 
> so, then it's a hard NAK from me.  It's the onboard/netboot interface of 
> the MIPS Malta platform and it continues being used regularly, primarily 
> with QEMU setups, although I have actual Malta hardware in my lab too, 
> usually running 24/7.  It's one of the primary MIPS plaforms, cf. 
> arch/mips/configs/malta_defconfig.

I have a few more MIPS systems with PCnet32 chip on board. And this
driver was the first network driver for VMware. I see no reason to
remove it as it simply works.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH net-next] pcnet32: remove VLB support

[Simon Horman]

On Sun, Jan 11, 2026 at 12:40:56AM +0000, Maciej W. Rozycki wrote:
> [+cc Thomas, linux-mips]
> 
> On Fri, 9 Jan 2026, Simon Horman wrote:
> 
> > > This allows the code managing device instances to be simplified
> > > significantly. The VLB bus is very obsolete and last appeared on
> > > P5 Pentium-era hardware. Support for it has been removed from
> > > other drivers, and it is highly unlikely anyone is using it with
> > > modern Linux kernels.
> > > 
> > > Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
> > 
> > Hi Ethan,
> > 
> > I don't think this driver has received much attention for some time.
> > So, unless you have hardware to test changes on, I would suggest
> > either leaving it alone or, if we suspect there are no users,
> > removing it.
> 
>  You mean discarding the whole of drivers/net/ethernet/amd/pcnet32.c?  If 
> so, then it's a hard NAK from me.  It's the onboard/netboot interface of 
> the MIPS Malta platform and it continues being used regularly, primarily 
> with QEMU setups, although I have actual Malta hardware in my lab too, 
> usually running 24/7.  It's one of the primary MIPS plaforms, cf. 
> arch/mips/configs/malta_defconfig.

Thanks, that is valuable feedback.

I'm certainly not advocating removing drivers that have an active user-base.

> 
>  No attention means the driver just works, why wouldn't it?  It's no 
> rocket science.  FWIW I continue using several drivers that saw little to 
> no change recently across various platforms.

Interesting. Subjectively, I'd say that Networking drivers it can be a sign
that the devices aren't being used in the wild. But clearly that signal was
incorrect in this case.

>  As to VLB support, I guess nobody cares nowadays.  I used to have such a 
> system, but haven't seen one in some three decades now and never used this 
> driver with one.

That is also valuable feedback, thanks.

Re: [PATCH net-next] pcnet32: remove VLB support

[Simon Horman]

On Mon, Jan 12, 2026 at 11:09:05PM +0100, Thomas Bogendoerfer wrote:
> On Sun, Jan 11, 2026 at 12:40:56AM +0000, Maciej W. Rozycki wrote:
> > [+cc Thomas, linux-mips]
> > 
> > On Fri, 9 Jan 2026, Simon Horman wrote:
> > 
> > > > This allows the code managing device instances to be simplified
> > > > significantly. The VLB bus is very obsolete and last appeared on
> > > > P5 Pentium-era hardware. Support for it has been removed from
> > > > other drivers, and it is highly unlikely anyone is using it with
> > > > modern Linux kernels.
> > > > 
> > > > Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
> > > 
> > > Hi Ethan,
> > > 
> > > I don't think this driver has received much attention for some time.
> > > So, unless you have hardware to test changes on, I would suggest
> > > either leaving it alone or, if we suspect there are no users,
> > > removing it.
> > 
> >  You mean discarding the whole of drivers/net/ethernet/amd/pcnet32.c?  If 
> > so, then it's a hard NAK from me.  It's the onboard/netboot interface of 
> > the MIPS Malta platform and it continues being used regularly, primarily 
> > with QEMU setups, although I have actual Malta hardware in my lab too, 
> > usually running 24/7.  It's one of the primary MIPS plaforms, cf. 
> > arch/mips/configs/malta_defconfig.
> 
> I have a few more MIPS systems with PCnet32 chip on board. And this
> driver was the first network driver for VMware. I see no reason to
> remove it as it simply works.

Understood. Thanks for the valuable feedback.

Re: [PATCH net-next] pcnet32: remove VLB support

[Maciej W. Rozycki]

On Thu, 15 Jan 2026, Simon Horman wrote:

> >  No attention means the driver just works, why wouldn't it?  It's no 
> > rocket science.  FWIW I continue using several drivers that saw little to 
> > no change recently across various platforms.
> 
> Interesting. Subjectively, I'd say that Networking drivers it can be a sign
> that the devices aren't being used in the wild. But clearly that signal was
> incorrect in this case.

 A stable driver usually doesn't require attention.  A potential issue is 
using dangerous C language features or ones that have been obsoleted in a 
newer version of the standard, which cause compilation warnings or errors 
in a new version of the compiler.  But that depends on how a given driver 
was written in the first place.

  Maciej