Hi, On 3/29/21 3:39 PM, Rafael J. Wysocki wrote: > On Sunday, March 28, 2021 1:20:00 PM CEST Hans de Goede wrote: >> Commit 71da201f38df ("ACPI: scan: Defer enumeration of devices with >> _DEP lists") dropped the following 2 lines from acpi_init_device_object(): >> >> /* Assume there are unmet deps until acpi_device_dep_initialize() runs */ >> device->dep_unmet = 1; >> >> Leaving the initial value of dep_unmet at the 0 from the kzalloc(). This >> causes the acpi_bus_get_status() call in acpi_add_single_object() to >> actually call _STA, even though there maybe unmet deps, leading to errors >> like these: >> >> [ 0.123579] ACPI Error: No handler for Region [ECRM] (00000000ba9edc4c) >> [GenericSerialBus] (20170831/evregion-166) >> [ 0.123601] ACPI Error: Region GenericSerialBus (ID=9) has no handler >> (20170831/exfldio-299) >> [ 0.123618] ACPI Error: Method parse/execution failed >> \_SB.I2C1.BAT1._STA, AE_NOT_EXIST (20170831/psparse-550) >> >> Fix this by moving the acpi_scan_dep_init() call done for devices added >> during the second pass done by acpi_bus_scan() to inside >> acpi_add_single_object(), so that dep_unmet is properly initialized >> before the acpi_bus_get_status() call. > > I wonder why the change below can't be made instead. > > The behavior would be closer to the original then AFAICS. Right the behavior would be closer to the code before the 2 fase scan rework. But just actually making sure we have the right value in unmet_dep a tiny bit earlier seems cleaner to me. Note that the one acpi_add_single_object() call which actually sets the new init_dep parameter to true and the previous place of calling acpi_scan_dep_init() are very close together, here is the code before this patch: acpi_add_single_object(&device, handle, type, sta, !check_dep); if (!device) return AE_CTRL_DEPTH; acpi_scan_init_hotplug(device); if (!check_dep) acpi_scan_dep_init(); So we are only doing the acpi_scan_dep_init() call a tiny bit earlier and wrt which locks are being held when it gets called no changes are made since it is still called as part of the call-graph below acpi_bus_check_add(), I explicitly checked the locking situation because that was my one worry with this patch. And this new approach also has the advantage of not setting dep_unmet=1 (and never clearing it) for devices instantiated through: acpi_bus_register_early_device() acpi_bus_scan_fixed() acpi_add_power_resource() IOW while looking into fixing the regression of the errors being logged again I tried to do a cleaner fix then last time. With that said if you prefer the version you suggest let me know and I'll post a single v2 patch doing things that way. If you want to go with your suggestion, shall I then add a dep_unmet=0 statement to the 3 mentioned functions which leave it at 1 when going back to the old way of handling this ? Regards, Hans > > --- > drivers/acpi/scan.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > Index: linux-pm/drivers/acpi/scan.c > =================================================================== > --- linux-pm.orig/drivers/acpi/scan.c > +++ linux-pm/drivers/acpi/scan.c > @@ -1647,6 +1647,8 @@ void acpi_init_device_object(struct acpi > device_initialize(&device->dev); > dev_set_uevent_suppress(&device->dev, true); > acpi_init_coherency(device); > + /* Assume there are unmet deps to start with. */ > + device->dep_unmet = 1; > } > > void acpi_device_add_finalize(struct acpi_device *device) > @@ -1957,7 +1959,13 @@ static acpi_status acpi_bus_check_add(ac > return AE_CTRL_DEPTH; > > acpi_scan_init_hotplug(device); > - if (!check_dep) > + /* > + * If check_dep is true at this point, the device has no dependencies, > + * or the creation of the device object would have been postponed above. > + */ > + if (check_dep) > + device->dep_unmet = 0; > + else > acpi_scan_dep_init(device); > > out: > > >