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

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Friday, January 15, 2021 8:01:19 PM CET 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;
>  	}
>  

The above need to be fixed even if they don't make any difference in your case.

Anyway, if they don't make any difference for you, please boot plain 5.11-rc[34]
with the debug patch below applied and grep the dmesg output for "Dependencies"
again.

The check added to acpi_scan_check_dep() reduces the number of devices that may
be affected quite a bit.

---
 drivers/acpi/scan.c |   12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -1867,7 +1867,8 @@ static u32 acpi_scan_check_dep(acpi_hand
 	 * 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, "_ADR")
+	    || !acpi_has_method(handle, "_HID"))
 		return 0;
 
 	status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
@@ -1950,10 +1951,8 @@ static acpi_status acpi_bus_check_add(ac
 	if (type == ACPI_BUS_TYPE_DEVICE && check_dep) {
 		u32 count = acpi_scan_check_dep(handle);
 		/* Bail out if the number of recorded dependencies is not 0. */
-		if (count > 0) {
-			acpi_bus_scan_second_pass = true;
-			return AE_CTRL_DEPTH;
-		}
+		if (count > 0)
+			acpi_handle_info(handle, "Dependencies found\n");
 	}
 
 	acpi_add_single_object(&device, handle, type, sta);
@@ -1961,8 +1960,7 @@ static acpi_status acpi_bus_check_add(ac
 		return AE_CTRL_DEPTH;
 
 	acpi_scan_init_hotplug(device);
-	if (!check_dep)
-		acpi_scan_dep_init(device);
+	acpi_scan_dep_init(device);
 
 out:
 	if (!*adev_p)