Re: [PATCH] 8250: option 'force_polling' for buggy IRQs

From: Theodore Ts'o
Date: Thu Jul 28 2016 - 12:02:02 EST

On Thu, Jul 28, 2016 at 07:47:04AM -0700, Greg KH wrote:
> > I agree, and I thought about it, but since this is meant for a very limited
> > audience, I think a catch-all is the easiest solution - both in terms of
> > implementation as well as ease of use.
> >
> > It's not meant for general consumption anyway.
> Then I really don't want to have to maintain and support such a kernel
> option for 20+ years, just because of one broken system out there like
> this. There are workarounds for this, as you have seen, including
> booting with a "real" userspace, so I don't want to take this patch.

One way to make this a bit more general purpose would be too add a way
to configure ttyS0 completely --- e.g., being able to specify the
port, irq, uart type, flags, etc. It still wouldn't be needed except
for very rarely (since either serial ports use self-configuring buses
--- e.g., USB, PCI, etc.) or they use the legacy x86 ports.

So perhaps Greg might be more willing to take that kind of change, but
even then, it could be argued that the maintaining such a kernel
option for just a few non-standard or broken systems is still not
worth it, but it would at least be somewhat more general purpose.

- Ted