Re: [PATCH 0/3] x86/PCI: Clip only partial E820 overlaps

From: Hans de Goede <hdegoede@redhat.com>
To: Bjorn Helgaas <helgaas@kernel.org>,
	"Rafael J . Wysocki" <rjw@rjwysocki.net>,
	Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>,
	Ingo Molnar <mingo@redhat.com>
Cc: "Mika Westerberg" <mika.westerberg@linux.intel.com>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Myron Stowe" <myron.stowe@redhat.com>,
	"Juha-Pekka Heikkila" <juhapekka.heikkila@gmail.com>,
	"Benoit Grégoire" <benoitg@coeus.ca>,
	"Hui Wang" <hui.wang@canonical.com>,
	"Kai-Heng Feng" <kai.heng.feng@canonical.com>,
	linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	"Bjorn Helgaas" <bhelgaas@google.com>
Subject: Re: [PATCH 0/3] x86/PCI: Clip only partial E820 overlaps
Date: Fri, 4 Mar 2022 15:15:16 +0100	[thread overview]
Message-ID: <4836963c-7a1e-7452-eb88-454f2b75e407@redhat.com> (raw)
In-Reply-To: <20220304035110.988712-1-helgaas@kernel.org>

Hi Bjorn,

On 3/4/22 04:51, Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@google.com>
> 
> This is based on Hans' extensive debugging and patch at
> https://lore.kernel.org/r/20220228105259.230903-1-hdegoede@redhat.com
> and applies on 7e57714cd0ad ("Linux 5.17-rc6").
> 
> This is basically the same idea (applying the 4dc2287c1805 workaround only
> when an E820 region *partially* overlaps a host bridge window), but I think
> it's a little simpler.
> 
> This also adds a little dmesg output when clipping, which should make
> future debugging easier.
> 
> I bcc'd several folks who didn't have public email addresses in the RedHat
> bugzilla or Launchpad.  If you review or test this, I'd be happy to
> acknowledge that.
> 
> Bjorn Helgaas (3):
>   x86/PCI: Eliminate remove_e820_regions() common subexpressions
>   x86/PCI: Log host bridge window clipping for E820 regions
>   x86/PCI: Preserve host bridge windows completely covered by E820

Thanks, I agree that this is better then my fix I also like the logging
added to 2/3 which lets us know if the commit 4dc2287c1805 workaround
is active.

I have one small remark on 3/3. Regardless of that getting addressed
the entire series is:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

I've done a Fedora test kernel build of 5.16.12 with these 3 patches
added and asked the reporters of:

https://bugzilla.redhat.com/show_bug.cgi?id=1868899
(ideapad touchpad bug)

and:

https://bugzilla.redhat.com/show_bug.cgi?id=2029207
(Lenovo x1 carbon gen 2 regression with my bios-data based fix_

to test the rpms and to collect dmesg. On the X1C2 this should show
the new logging from 2/3 "in action" and on the ideapad the touchpad
should still work...

Regards,

Hans