Hi, On 6/15/21 12:59 PM, Rafael J. Wysocki wrote: > On Tue, Jun 15, 2021 at 12:26 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: >> >> On some Lenovo laptops the base-addrsss of some PCI devices is left >> at 0 at boot: >> >> [ 0.283145] pci 0000:00:15.0: [8086:34e8] type 00 class 0x0c8000 >> [ 0.283217] pci 0000:00:15.0: reg 0x10: [mem 0x00000000-0x00000fff 64bit] >> [ 0.285117] pci 0000:00:15.1: [8086:34e9] type 00 class 0x0c8000 >> [ 0.285189] pci 0000:00:15.1: reg 0x10: [mem 0x00000000-0x00000fff 64bit] >> >> There is a _CRS method for these devices, which simply returns the >> configured 0 address. This is causing the PCI core to not assign >> memory to these PCI devices and is causing these errors: >> >> [ 0.655335] pci 0000:00:15.0: BAR 0: no space for [mem size 0x00001000 64bit] >> [ 0.655337] pci 0000:00:15.0: BAR 0: failed to assign [mem size 0x00001000 64bit] >> [ 0.655339] pci 0000:00:15.1: BAR 0: no space for [mem size 0x00001000 64bit] >> [ 0.655340] pci 0000:00:15.1: BAR 0: failed to assign [mem size 0x00001000 64bit] >> >> This happens specifically for the designware I2C PCI devices on these >> laptops, causing I2C-HID attached touchpads/touchscreens to not work. >> >> Booting with nocrs on these devices results in the kernel itself >> assigning memory to these devices, fixing things: >> >> [ 0.355716] pci 0000:00:15.0: BAR 0: assigned [mem 0x29c000000-0x29c000fff 64bit] >> [ 0.355783] pci 0000:00:15.1: BAR 0: assigned [mem 0x29c001000-0x29c001fff 64bit] >> >> At least the following models are known to be affected by this (but there >> might be more): >> >> Lenovo IdeaPad 3 15IIL05 81WE >> Lenovo IdeaPad 5 14IIL05 81YH >> >> Add an extra check for the base-address being 0 to >> acpi_pci_root_validate_resources() and reject IOMEM resources where this >> is the case, to fix this issue. >> >> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1871793 >> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1868899 >> BugLink: https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe/+bug/1878279 >> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> >> --- >> Note we could instead add the known to be affected models to the >> pci_crs_quirks table in arch/x86/pci/acpi.c, but it is likely that more >> systems are affected and a more generic fix seems better in general. > > Also, a memory resource starting at 0 is not usable in Linux anyway > AFAICS, at least on x86. Right, but I was wondering about other arches. Maybe wrap the new check in "#if IS_ENABLED(CONFIG_X86)" ? Regards, Hans > >> --- >> drivers/acpi/pci_root.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c >> index dcd593766a64..6cd2ca551005 100644 >> --- a/drivers/acpi/pci_root.c >> +++ b/drivers/acpi/pci_root.c >> @@ -686,6 +686,13 @@ static void acpi_pci_root_validate_resources(struct device *dev, >> if (!(res1->flags & type)) >> goto next; >> >> + if ((type & IORESOURCE_MEM) && res1->start == 0) { >> + dev_info(dev, "host bridge window %pR (ignored, start address not set)\n", >> + res1); > > Makes sense to me (small nit: I wouldn't break the like above). > >> + free = true; >> + goto next; >> + } >> + >> /* Exclude non-addressable range or non-addressable portion */ >> end = min(res1->end, root->end); >> if (end <= res1->start) { >> -- >
