Hi, So I have a laptop with two M.2 slot / PCIe port: 00:06.0 PCI bridge: Intel Corporation 12th Gen Core Processor PCI Express x4 Controller #0 (rev 04) 00:1d.0 PCI bridge: Intel Corporation Device 51b0 (rev 01) Apparently 00:06.0 is wired to the CPU directly and the 00:1d.0 is weird to the PCH. Both of them can be disabled independently in UEFI settings, and both have an NVMe drive installed. Currently only the drive on the "CPU slot" is used, with both Windows and Linux installed. The other drive has been wiped and remains unused for now due to the issue I'm reporting here. The problem I am having is that for some reason, when the "PCH slot" is enabled, Linux has estimatedly only < 50% chance to detect the battery. If it has failed to do so, seemingly I have to "cold reboot" (I mean like, shutdown normally and power on again, but not just reboot or S3 suspend) to get it back, in which case the successful rate is the same. I track it down to have the following sysfs findings: [tom@corebook ~]$ ls -Al '/sys/devices/pci0000:00/0000:00:1f.0/PNP0C09:00/' total 0 -rw-r--r-- 1 root root 4096 Sep 17 11:01 driver_override lrwxrwxrwx 1 root root 0 Sep 17 11:01 firmware_node -> ../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:0b/PNP0C09:00 drwxr-xr-x 3 root root 0 Sep 17 11:01 INT33D3:00 drwxr-xr-x 3 root root 0 Sep 17 11:01 INT33D4:00 drwxr-xr-x 3 root root 0 Sep 17 11:01 INTC1046:01 drwxr-xr-x 3 root root 0 Sep 17 11:01 INTC1046:02 drwxr-xr-x 3 root root 0 Sep 17 11:01 INTC1046:03 drwxr-xr-x 3 root root 0 Sep 17 11:01 INTC1048:00 -r--r--r-- 1 root root 4096 Sep 17 11:01 modalias drwxr-xr-x 3 root root 0 Sep 17 11:01 PNP0C0D:00 drwxr-xr-x 2 root root 0 Sep 17 11:01 power lrwxrwxrwx 1 root root 0 Sep 17 11:01 subsystem -> ../../../../bus/platform -rw-r--r-- 1 root root 4096 Sep 17 11:01 uevent -r--r--r-- 1 root root 4096 Sep 17 11:01 waiting_for_supplier [tom@corebook ~]$ ls -Al '/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:0b/PNP0C09:00/PNP0C0A:00/' total 0 -r--r--r-- 1 root root 4096 Sep 17 11:02 hid -r--r--r-- 1 root root 4096 Sep 17 11:02 modalias -r--r--r-- 1 root root 4096 Sep 17 11:02 path drwxr-xr-x 2 root root 0 Sep 17 11:02 power -r--r--r-- 1 root root 4096 Sep 17 11:02 status lrwxrwxrwx 1 root root 0 Sep 17 11:01 subsystem -> ../../../../../../../bus/acpi -rw-r--r-- 1 root root 4096 Sep 17 11:01 uevent -r--r--r-- 1 root root 4096 Sep 17 11:02 uid whereas if the "PCH slot" is disabled, or if it succeeded in the "detection trial": [tom@corebook ~]$ ls -Al '/sys/devices/pci0000:00/0000:00:1f.0/PNP0C09:00/' total 0 -rw-r--r-- 1 root root 4096 Sep 17 11:56 driver_override lrwxrwxrwx 1 root root 0 Sep 17 11:56 firmware_node -> ../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:0b/PNP0C09:00 drwxr-xr-x 3 root root 0 Sep 17 11:53 INT33D3:00 drwxr-xr-x 3 root root 0 Sep 17 11:53 INT33D4:00 drwxr-xr-x 3 root root 0 Sep 17 11:53 INTC1046:01 drwxr-xr-x 3 root root 0 Sep 17 11:53 INTC1046:02 drwxr-xr-x 3 root root 0 Sep 17 11:53 INTC1046:03 drwxr-xr-x 3 root root 0 Sep 17 11:53 INTC1048:00 -r--r--r-- 1 root root 4096 Sep 17 11:56 modalias drwxr-xr-x 3 root root 0 Sep 17 11:53 PNP0C0A:00 drwxr-xr-x 3 root root 0 Sep 17 11:53 PNP0C0D:00 drwxr-xr-x 2 root root 0 Sep 17 11:56 power lrwxrwxrwx 1 root root 0 Sep 17 11:53 subsystem -> ../../../../bus/platform -rw-r--r-- 1 root root 4096 Sep 17 11:53 uevent -r--r--r-- 1 root root 4096 Sep 17 11:56 waiting_for_supplier [tom@corebook ~]$ ls -Al '/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:0b/PNP0C09:00/PNP0C0A:00/' total 0 lrwxrwxrwx 1 root root 0 Sep 17 11:53 driver -> ../../../../../../../bus/acpi/drivers/battery -r--r--r-- 1 root root 4096 Sep 17 11:56 hid -r--r--r-- 1 root root 4096 Sep 17 11:56 modalias -r--r--r-- 1 root root 4096 Sep 17 11:56 path lrwxrwxrwx 1 root root 0 Sep 17 11:56 physical_node -> ../../../../../../pci0000:00/0000:00:1f.0/PNP0C09:00/PNP0C0A:00 drwxr-xr-x 2 root root 0 Sep 17 11:56 power drwxr-xr-x 3 root root 0 Sep 17 11:53 power_supply -r--r--r-- 1 root root 4096 Sep 17 11:56 status lrwxrwxrwx 1 root root 0 Sep 17 11:53 subsystem -> ../../../../../../../bus/acpi -rw-r--r-- 1 root root 4096 Sep 17 11:53 uevent -r--r--r-- 1 root root 4096 Sep 17 11:56 uid drwxr-xr-x 3 root root 0 Sep 17 11:53 wakeup As you can see, the "physical node" `PNP0C0A:00` is gone in the failing case and the "firmware node" of it hence has nothing to "attach"(?) to, so the battery driver will therefore see nothing. (The parent device `PNP0C09:00` is managed by the driver `ec`, for the record.) I don't know if this issue is caused by a certain bug or flaw in the UEFI/EC firmware, but the problem does not seem to occur in Windows. Either way, I'm writing to see if I can get any insight from you guys on what might be the potential reason/rationale here. (Note that as mentioned, it does not always occur in Linux either, so it looks like some kind of "mapping race"(?) to me.) P.S. While there are some ACPI errors (as it does for most laptops these days), I don't see any potentially relevant difference in the kernel log between the successful and failing cases. The only difference is that in the successful case, there's the extra expected line of "battery detected". Anyway, I'm adding the warnings/errors in the kernel log that might be remotely relevant, but please do note that I see them all in both cases: ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.I2C0.TPD0], AE_NOT_FOUND (20230331/dswload2-162) ACPI Error: AE_NOT_FOUND, During name lookup/catalog (20230331/psobject-220) pnp 00:02: disabling [mem 0xc0000000-0xcfffffff] because it overlaps 0000:00:02.0 BAR 9 [mem 0x00000000-0xdfffffff 64bit pref] hpet_acpi_add: no address or irqs in _CRS i8042: PNP: PS/2 appears to have AUX port disabled, if this is incorrect please boot with i8042.nopnp ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.TSR1], AE_NOT_FOUND (20230331/psargs-330) ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC.SEN1._TMP due to previous error (AE_NOT_FOUND) (20230331/psparse-529) ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PC00.LPCB.HEC.TSR1], AE_NOT_FOUND (20230331/psargs-330) ACPI Error: Aborting method \_SB.PC00.LPCB.H_EC.SEN1._TMP due to previous error (AE_NOT_FOUND) (20230331/psparse-529) intel-hid INTC1070:00: failed to enable HID power button resource: resource sanity check: requesting [mem 0x00000000fedc0000-0x00000000fedcffff], which spans more than pnp 00:02 [mem 0xfedc0000-0xfedc7fff] caller igen6_probe+0x1a0/0x8d0 [igen6_edac] mapping multiple BARs i2c i2c-11: Systems with more than 4 memory slots not supported yet, not instantiating SPD Regards, Tom
