On Thu, May 20, 2021 at 8:33 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > > On Thu, May 20, 2021 at 4:11 PM Daniel Scally <djrscally@xxxxxxxxx> wrote: > > > > In some ACPI tables we encounter, devices use the _DEP method to assert > > a dependence on other ACPI devices as opposed to the OpRegions that the > > specification intends. We need to be able to find those devices "from" > > the dependee, so add a callback and a wrapper to walk over the > > acpi_dep_list and return the dependent ACPI device. > > > > Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > > Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx> > > --- > > Changes since v3: > > > > Both new functions were renamed. > > > > drivers/acpi/scan.c | 38 ++++++++++++++++++++++++++++++++++++++ > > include/acpi/acpi_bus.h | 1 + > > 2 files changed, 39 insertions(+) > > > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > > index 195635c3462b..1a76fbdfa669 100644 > > --- a/drivers/acpi/scan.c > > +++ b/drivers/acpi/scan.c > > @@ -2105,6 +2105,21 @@ static void acpi_bus_attach(struct acpi_device *device, bool first_pass) > > device->handler->hotplug.notify_online(device); > > } > > > > +static int acpi_return_dep_dev(struct acpi_dep_data *dep, void *data) > > What about calling this acpi_get_first_consumer_cb()? Or acpi_dev_get_first_consumer_dev_cb() if you want to be super-precise? > > > +{ > > + struct acpi_device *adev; > > + int ret; > > + > > + ret = acpi_bus_get_device(dep->consumer, &adev); > > + if (ret) > > + /* If we don't find an adev then we want to continue parsing */ > > + return 0; > > + > > + *(struct acpi_device **)data = adev; > > And it can do the get_device() here, can't it? > > So maybe use acpi_bus_get_acpi_device() instead of > acpi_bus_get_device()? Would be simpler. > > > + > > + return 1; > > +} > > + > > static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data) > > { > > struct acpi_device *adev; > > @@ -2168,6 +2183,29 @@ void acpi_dev_clear_dependencies(struct acpi_device *supplier) > > } > > EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies); > > > > +/** > > + * acpi_dev_get_dependent_dev - Return ACPI device dependent on @supplier > > And what about calling this acpi_get_first_consumer() ? Or acpi_dev_get_first_consumer_dev() (in analogy with the above)? > > + * @supplier: Pointer to the dependee device > > + * > > + * Returns the first &struct acpi_device which declares itself dependent on > > + * @supplier via the _DEP buffer, parsed from the acpi_dep_list. > > + * > > + * The caller is responsible for putting the reference to adev when it is no > > + * longer needed. > > + */ > > +struct acpi_device *acpi_dev_get_dependent_dev(struct acpi_device *supplier) > > +{ > > + struct acpi_device *adev = NULL; > > + > > + acpi_walk_dep_device_list(supplier->handle, acpi_return_dep_dev, &adev); > > + > > + if (adev) > > + get_device(&adev->dev); > > + > > + return adev; > > +} > > +EXPORT_SYMBOL_GPL(acpi_dev_get_dependent_dev); > > + > > /** > > * acpi_bus_scan - Add ACPI device node objects in a given namespace scope. > > * @handle: Root of the namespace scope to scan. > > diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h > > index 0b2c4f170f4d..68d378207704 100644 > > --- a/include/acpi/acpi_bus.h > > +++ b/include/acpi/acpi_bus.h > > @@ -692,6 +692,7 @@ static inline bool acpi_device_can_poweroff(struct acpi_device *adev) > > bool acpi_dev_hid_uid_match(struct acpi_device *adev, const char *hid2, const char *uid2); > > > > void acpi_dev_clear_dependencies(struct acpi_device *supplier); > > +struct acpi_device *acpi_dev_get_dependent_dev(struct acpi_device *supplier); > > struct acpi_device * > > acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv); > > struct acpi_device * > > -- > > 2.25.1 > >