Re: `ucsi_acpi: probe of USBC000:00 failed with error -12` on Dell XPS 13 9360/9370

[Heikki Krogerus]

On Fri, May 18, 2018 at 10:04:02PM +0200, Rafael J. Wysocki wrote:
> On Fri, May 18, 2018 at 5:15 PM, Greg Kroah-Hartman
> > Given that Windows works with this same set of ACPI tables, perhaps the
> > requirement isn't that this memory location be uncached?
> >
> > We shouldn't have to fix up ACPI tables just for Linux, we've been down
> > that path before :(
> 
> Yes, pretty much.

That's not what I'm suggesting. AFAIK these Dell laptops are the only
ones with this problem, so if we accept this, I fear it means we have
to start maintaining DMI quirk table in the driver, and then:

if (dell)
        ioremap_cache()
else
        ioremap_nocache()

I was really hoping we could avoid that. Or is there something else we
can do in the driver?

I have no idea how the windows driver works, so I will double check
and test this next week, but our driver has really worked fine so far.


Thanks,

-- 
heikki