Re: ACPI scan regression -> Boot fail on Cherrytrail w/ 5.11-rc3

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 1/15/21 10:57 PM, Hans de Goede wrote:
> 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.

Good news, I can confirm that these 2 changes fix this on my other reproducer too.

FYI: My other reporducer was 5.10.2 with the ACPI scan changes backported for testing
on a Lenovo Yoga Tablet 2 1051L.

Regards,

Hans