Hi, On 1/15/21 8:01 PM, Rafael J. Wysocki wrote: > On Friday, January 15, 2021 5:41:57 PM CET Pierre-Louis Bossart wrote: >> >>>>> [ 0.516336] ACPI: \_SB_.PCI0.BRCM: Dependencies found >>>> >>>> Ah, that is enlightening, that is not supposed to happen, that device >>>> has both an _ADR and an _HID method which is not allowed according >>>> to the spec. >> >> it's not an uncommon issue for audio codecs, here's three examples: >> >> Device (RTK1) >> { >> Name (_ADR, Zero) // _ADR: Address >> Name (_HID, "10EC5670") // _HID: Hardware ID >> Name (_CID, "10EC5670") // _CID: Compatible ID >> Name (_DDN, "ALC5642") // _DDN: DOS Device Name >> >> Device (MAXM) >> { >> Name (_ADR, Zero) // _ADR: Address >> Name (_HID, "193C9890") // _HID: Hardware ID >> Name (_CID, "193C9890") // _CID: Compatible ID >> Name (_DDN, "Maxim 98090 Codec ") // _DDN: DOS Device Name >> >> Device (TISW) >> { >> Name (_ADR, Zero) // _ADR: Address >> Name (_HID, "104C227E") // _HID: Hardware ID >> Name (_CID, "104C227E") // _CID: Compatible ID >> >> It's been that way for years... >> >>>> Can you try a clean 5.11 kernel (so none of the previous >>>> debug patches) with the following change added: >>>> >>>> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c >>>> index 1f27f74cc83c..93954ac3bfcc 100644 >>>> --- a/drivers/acpi/scan.c >>>> +++ b/drivers/acpi/scan.c >>>> @@ -1854,7 +1854,8 @@ static u32 acpi_scan_check_dep(acpi_handle handle) >>>> * 2. ACPI nodes describing USB ports. >>>> * Still, checking for _HID catches more then just these cases ... >>>> */ >>>> - if (!acpi_has_method(handle, "_DEP") || !acpi_has_method(handle, "_HID")) >>>> + if (!acpi_has_method(handle, "_DEP") || !acpi_has_method(handle, "_HID") || >>>> + acpi_has_method(handle, "_ADR")) >>>> return 0; >>>> >>>> status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices); >>>> >>>> >>>>> [ 0.517490] ACPI: \_SB_.PCI0.LNPW: Dependencies found >>>> >>>> And idem. for this one. >>>> >>>> That might very well fix this. >> >> Nope, no luck with this patch. boot still stuck. > > OK, thanks! > > Now, there is a theory to test and some more debug work to do. > > First, the kernel should not crash outright if some ACPI device objects are > missing which evidently happens here. There may be some problems resulting > from that, but the crash indicates a code bug in the kernel. > > Apparently, something expects the device objects to be there so badly, that it > crashes right away when they aren't there. One of the issues that may cause > that to happen are mistakes around the acpi_bus_get_device() usage and I found > two of them, so below is a patch to test. > > Please apply to plain 5.11-rc3 (or -rc4 when it is out) and see if that makes > any difference. > > --- > drivers/acpi/scan.c | 3 +-- > drivers/usb/core/usb-acpi.c | 3 +-- > 2 files changed, 2 insertions(+), 4 deletions(-) > > Index: linux-pm/drivers/acpi/scan.c > =================================================================== > --- linux-pm.orig/drivers/acpi/scan.c > +++ linux-pm/drivers/acpi/scan.c > @@ -2120,8 +2120,7 @@ void acpi_walk_dep_device_list(acpi_hand > mutex_lock(&acpi_dep_list_lock); > list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) { > if (dep->supplier == handle) { > - acpi_bus_get_device(dep->consumer, &adev); > - if (!adev) > + if (acpi_bus_get_device(dep->consumer, &adev)) > continue; > > adev->dep_unmet--; > Index: linux-pm/drivers/usb/core/usb-acpi.c > =================================================================== > --- linux-pm.orig/drivers/usb/core/usb-acpi.c > +++ linux-pm/drivers/usb/core/usb-acpi.c > @@ -163,10 +163,9 @@ usb_acpi_get_companion_for_port(struct u > } else { > parent_handle = usb_get_hub_port_acpi_handle(udev->parent, > udev->portnum); > - if (!parent_handle) > + if (!parent_handle || acpi_bus_get_device(parent_handle, &adev)) > return NULL; > > - acpi_bus_get_device(parent_handle, &adev); > port1 = port_dev->portnum; > } > I can confirm that these changes fix the intermittent boot issue I had with 5.11-rc3 on the Minix Neo z83-4. It is getting a bit late here, so I will test my second (also intermittent) reproducer tomorrow. Regards, Hans