Re: [RFC/RFT PATCH 0/2] disable_hest quirk on HP m400 with bad UEFI firmwware

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Tue, Jul 03, 2018 at 04:47:51PM +0100, Ian Campbell wrote:
> On Tue, 2018-07-03 at 17:17 +0200, Ard Biesheuvel wrote:
> > On 3 July 2018 at 10:44, Ian Campbell <ijc@debian.org> wrote:
> > > On Thu, 2018-06-28 at 12:25 +0200, Ard Biesheuvel wrote:
> > > > I understand the desire to keep running these M400s as long as they
> > > > have some life left in them, but the reality is that they are end of
> > > > life already, and not many were manufactured to begin with.
> > > 
> > > Linux has a long history of supporting such devices so long as there is
> > > someone around willing to keep them running (witness for example how
> > > long x86/voyager lived with just 1 in existence in a motivated
> > > developer's basement, probably some number of entire architectures and
> > > I bet a not insubstantial chunk of the platform support in arch/arm).
> > > 
> > 
> > I wonder how many such quirks fall into the 'user cannot be bothered
> > to add a kernel command line option' category.
> 
> I don't know the overall picture, but the very first one I happened to
> look at in arch/x86/kernel/acpi/boot.c (picked by grepping for quirk
> and looking for acpi) just now was half a dozen quirks setting
> acpi_skip_timer_override which is also settable on the command line.
> There's also a bunch in there which just disable ACPI completely which
> is also possible on the command line.
> 
> My gut feeling is that these are the rule not the exception.
> 
> > > So, I think DMI quirks are probably, in reality, inevitable unless
> > > you
> > > think firmware authors are going to be infaliable or the
> > > testing/certification suites never has any gaps in it.
> > > 
> > 
> > Oh, obviously. But this is exactly my point about flood gates: we know
> > we need implement support for them, but that fact alone does not
> > justify adding quirks for dead platforms for issues that can be
> > trivially worked around.
> 
> Is m400 really dead? There certainly seem to be people around who care
> about keeping it running and have access to them.

I do not think anybody is preventing that, it is just that we do not
see the reason for adding a DMI quirk to the mainline kernel to enable
a platform with broken firmware that cripples one of the main feature
it is supposed to implement, we can go on forever about this but that's
the gist.

Thanks,
Lorenzo