On Tue, Nov 20, 2018 at 06:30:22PM +0000, Schmauss, Erik wrote: > > > -----Original Message----- > > From: Greg KH [mailto:greg@xxxxxxxxx] > > Sent: Tuesday, November 20, 2018 1:12 AM > > To: Jean Delvare <jdelvare@xxxxxxx> > > Cc: stable@xxxxxxxxxxxxxxx; Guenter Roeck <linux@xxxxxxxxxxxx>; > > Schmauss, Erik <erik.schmauss@xxxxxxxxx>; Wysocki, Rafael J > > <rafael.j.wysocki@xxxxxxxxx> > > Subject: Re: Please revert "ACPICA: AML interpreter: add region addresses in > > global list during initialization" > > > > On Tue, Nov 20, 2018 at 10:03:59AM +0100, Jean Delvare wrote: > > > On Tue, 20 Nov 2018 09:54:19 +0100, Greg KH wrote: > > > > On Tue, Nov 20, 2018 at 09:46:49AM +0100, Jean Delvare wrote: > > > > > Dear stable kernel team, > > > > > > > > > > In stable kernel 4.19.2, the following upstream commit was included: > > > > > > > > > > commit 4abb951b73ff0a8a979113ef185651aa3c8da19b > > > > > Author: Erik Schmauss > > > > > Date: Wed Oct 17 14:09:35 2018 -0700 > > > > > > > > > > ACPICA: AML interpreter: add region addresses in global list > > > > > during initialization > > > > > > > > > > (...) > Hi, > > > > > > Please revert this commit from future stable kernels on all > > > > > affected branches (I think only 4.18.19 and 4.19.2 are affected at > > > > > the moment, but maybe other affected releases are in the works > > already). > > > > > > > > Ok, I'll go revert this, but shouldn't it also be reverted in > > > > Linus's tree as well? > > > > > Hello, > > > No. As I understand it (with my limited knowledge of ACPICA), the > > > change itself is correct. The problem is that it will detect resource > > > conflicts which were unnoticed before, and that will prevent drivers > > > from loading. Some of them may be addressed with driver fixes or new > > > drivers. Others are false positives (due to bogus BIOS) which users > > > will have to work around with acpi_resource_conflicts=lax. We have > > > been through this before, nothing new really, but it takes years to > > > address such problems. This just can't be done in stable kernel series. > > I would like to give you more context. > > There was a fairly complicated change that occurred in 4.17 and we > caused a regression by forgetting to add region addresses in a global list > during operation region initialization. We found the regression when bug > reporters tried to boot their macbook pro and asus laptop and saw that > there was a difference in behavior when drivers are being loaded > > So what I am trying to say is that we have been emitting these errors for a > while before we caused the regression. The goal with this patch is to keep > the behavior the same as kernels older than 4.17 where warnings are > printed to dmesg due to resource conflicts. Ok, so does this mean it belongs in 4.19.y? (4.18.y is about to go end-of-life in a few hours) Or does this mean it should just stay in 4.20? confused, greg k-h
