On Fri, Aug 30, 2019 at 4:34 PM Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: > > When the commit 68bdb6773289 > > ("ACPI: add support for ACPI reconfiguration notifiers") > > introduced reconfiguration notifiers it misses the point that the ACPI table, > which may be loaded and then unloaded via ConfigFS, can contain devices that are > not enumerated by their parents. > > In such case the stale platform device is dangling in the system while the rest > of the devices from the same table are already gone. > > Introduce acpi_platform_device_remove_notify() notifier that, in similar way to > I²C or SPI buses, unregisters the platform devices on table removal event. > > Depends-on: 00500147cbd3 ("drivers: Introduce device lookup variants by ACPI_COMPANION device") > Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > --- > drivers/acpi/acpi_platform.c | 43 ++++++++++++++++++++++++++++++++++++ > drivers/acpi/scan.c | 1 + > 2 files changed, 44 insertions(+) > > diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c > index 00ec4f2bf015..dfcd6210828e 100644 > --- a/drivers/acpi/acpi_platform.c > +++ b/drivers/acpi/acpi_platform.c > @@ -31,6 +31,44 @@ static const struct acpi_device_id forbidden_id_list[] = { > {"", 0}, > }; > > +static struct platform_device *acpi_platform_device_find_by_adev(struct acpi_device *adev) > +{ > + struct device *dev; > + > + dev = bus_find_device_by_acpi_dev(&platform_bus_type, adev); > + return dev ? to_platform_device(dev) : NULL; > +} > + > +static int acpi_platform_device_remove_notify(struct notifier_block *nb, > + unsigned long value, void *arg) > +{ > + struct acpi_device *adev = arg; > + struct platform_device *pdev; > + > + switch (value) { > + case ACPI_RECONFIG_DEVICE_ADD: > + /* Nothing to do here */ > + break; > + case ACPI_RECONFIG_DEVICE_REMOVE: > + if (!acpi_device_enumerated(adev)) > + break; > + > + pdev = acpi_platform_device_find_by_adev(adev); > + if (!pdev) > + break; > + > + platform_device_unregister(pdev); > + put_device(&pdev->dev); > + break; > + } > + > + return NOTIFY_OK; > +} > + > +static struct notifier_block acpi_platform_notifier = { > + .notifier_call = acpi_platform_device_remove_notify, > +}; > + > static void acpi_platform_fill_resource(struct acpi_device *adev, > const struct resource *src, struct resource *dest) > { > @@ -130,3 +168,8 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev, > return pdev; > } > EXPORT_SYMBOL_GPL(acpi_create_platform_device); > + > +void __init acpi_platform_init(void) > +{ > + acpi_reconfig_notifier_register(&acpi_platform_notifier); > +} > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index aad6be5c0af0..915650bf519f 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -2174,6 +2174,7 @@ int __init acpi_scan_init(void) > acpi_pci_root_init(); > acpi_pci_link_init(); > acpi_processor_init(); > + acpi_platform_init(); > acpi_lpss_init(); > acpi_apd_init(); > acpi_cmos_rtc_init(); > -- Applying (with minor modifications) as 5.5 material, thanks!