| Message ID | 20220209161342.91721-1-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | x86/PCI: revert "Ignore E820 reservations for bridge windows on newer systems" | expand |
On Wed, Feb 9, 2022 at 5:14 PM Hans de Goede <hdegoede@redhat.com> wrote: > > Commit 7f7b4236f204 ("x86/PCI: Ignore E820 reservations for bridge windows > on newer systems") fixes the touchpad not working on laptops like > the Lenovo IdeaPad 3 15IIL05 and the Lenovo IdeaPad 5 14IIL05, as well as > fixing thunderbolt hotplug issues on the Lenovo Yoga C940. > > Unfortunately it turns out that this is causing issues with suspend/resume > on Lenovo ThinkPad X1 Carbon Gen 2 laptops. So, per the no regressions > policy, rever this. Note I'm looking into another fix for the issues this > fixed. > > Fixes: 7f7b4236f204 ("x86/PCI: Ignore E820 reservations for bridge windows on newer systems") > BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2029207 > Signed-off-by: Hans de Goede <hdegoede@redhat.com> Applied as 5.17-rc material and pushed out for -next, thanks! > --- > arch/x86/kernel/resource.c | 23 +---------------------- > 1 file changed, 1 insertion(+), 22 deletions(-) > > diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c > index 9ae64f9af956..9b9fb7882c20 100644 > --- a/arch/x86/kernel/resource.c > +++ b/arch/x86/kernel/resource.c > @@ -1,5 +1,4 @@ > // SPDX-License-Identifier: GPL-2.0 > -#include <linux/dmi.h> > #include <linux/ioport.h> > #include <asm/e820/api.h> > > @@ -24,31 +23,11 @@ static void resource_clip(struct resource *res, resource_size_t start, > res->start = end + 1; > } > > -/* > - * Some BIOS-es contain a bug where they add addresses which map to > - * system RAM in the PCI host bridge window returned by the ACPI _CRS > - * method, see commit 4dc2287c1805 ("x86: avoid E820 regions when > - * allocating address space"). To avoid this Linux by default excludes > - * E820 reservations when allocating addresses since 2010. > - * In 2019 some systems have shown-up with E820 reservations which cover > - * the entire _CRS returned PCI host bridge window, causing all attempts > - * to assign memory to PCI BARs to fail if Linux uses E820 reservations. > - * > - * Ideally Linux would fully stop using E820 reservations, but then > - * the old systems this was added for will regress. > - * Instead keep the old behavior for old systems, while ignoring the > - * E820 reservations for any systems from now on. > - */ > static void remove_e820_regions(struct resource *avail) > { > - int i, year = dmi_get_bios_year(); > + int i; > struct e820_entry *entry; > > - if (year >= 2018) > - return; > - > - pr_info_once("PCI: Removing E820 reservations from host bridge windows\n"); > - > for (i = 0; i < e820_table->nr_entries; i++) { > entry = &e820_table->entries[i]; > > -- > 2.33.1 >
diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c index 9ae64f9af956..9b9fb7882c20 100644 --- a/arch/x86/kernel/resource.c +++ b/arch/x86/kernel/resource.c @@ -1,5 +1,4 @@ // SPDX-License-Identifier: GPL-2.0 -#include <linux/dmi.h> #include <linux/ioport.h> #include <asm/e820/api.h> @@ -24,31 +23,11 @@ static void resource_clip(struct resource *res, resource_size_t start, res->start = end + 1; } -/* - * Some BIOS-es contain a bug where they add addresses which map to - * system RAM in the PCI host bridge window returned by the ACPI _CRS - * method, see commit 4dc2287c1805 ("x86: avoid E820 regions when - * allocating address space"). To avoid this Linux by default excludes - * E820 reservations when allocating addresses since 2010. - * In 2019 some systems have shown-up with E820 reservations which cover - * the entire _CRS returned PCI host bridge window, causing all attempts - * to assign memory to PCI BARs to fail if Linux uses E820 reservations. - * - * Ideally Linux would fully stop using E820 reservations, but then - * the old systems this was added for will regress. - * Instead keep the old behavior for old systems, while ignoring the - * E820 reservations for any systems from now on. - */ static void remove_e820_regions(struct resource *avail) { - int i, year = dmi_get_bios_year(); + int i; struct e820_entry *entry; - if (year >= 2018) - return; - - pr_info_once("PCI: Removing E820 reservations from host bridge windows\n"); - for (i = 0; i < e820_table->nr_entries; i++) { entry = &e820_table->entries[i];
Commit 7f7b4236f204 ("x86/PCI: Ignore E820 reservations for bridge windows on newer systems") fixes the touchpad not working on laptops like the Lenovo IdeaPad 3 15IIL05 and the Lenovo IdeaPad 5 14IIL05, as well as fixing thunderbolt hotplug issues on the Lenovo Yoga C940. Unfortunately it turns out that this is causing issues with suspend/resume on Lenovo ThinkPad X1 Carbon Gen 2 laptops. So, per the no regressions policy, rever this. Note I'm looking into another fix for the issues this fixed. Fixes: 7f7b4236f204 ("x86/PCI: Ignore E820 reservations for bridge windows on newer systems") BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2029207 Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- arch/x86/kernel/resource.c | 23 +---------------------- 1 file changed, 1 insertion(+), 22 deletions(-)