Yongxin Liu <yongxin.liu@xxxxxxxxxxxxx> writes: > This reverts commit 7b11e8989618581bc0226ad313264cdc05d48d86. > > Consider the following hardware setting. > > |-PNP0C14:00 > | |-- device #1 > |-PNP0C14:01 > | |-- device #2 > > When unloading wmi driver module, device #2 will be first unregistered. > But device_destroy() using MKDEV(0, 0) will locate PNP0C14:00 first > and unregister it. This is incorrect. Should use device_unregister() to > unregister the real parent device. > > Signed-off-by: Yongxin Liu <yongxin.liu@xxxxxxxxxxxxx> > --- > drivers/platform/x86/wmi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c > index 59e9aa0f9643..e16f660aa117 100644 > --- a/drivers/platform/x86/wmi.c > +++ b/drivers/platform/x86/wmi.c > @@ -1347,7 +1347,7 @@ static int acpi_wmi_remove(struct platform_device *device) > acpi_remove_address_space_handler(acpi_device->handle, > ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler); > wmi_free_devices(acpi_device); > - device_destroy(&wmi_bus_class, MKDEV(0, 0)); > + device_unregister((struct device *)dev_get_drvdata(&device->dev)); > > return 0; > } > @@ -1401,7 +1401,7 @@ static int acpi_wmi_probe(struct platform_device *device) > return 0; > > err_remove_busdev: > - device_destroy(&wmi_bus_class, MKDEV(0, 0)); > + device_unregister(wmi_bus_dev); > > err_remove_notify_handler: > acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY, Definitely! Good catch! device_create() will allow registering multiple devices with a zero major. Using device_destroy() with MKDEV(0, 0) will unregister an arbitrary one of them. I believe all of these should be reviewed and fixed up: drivers/nvme/host/fabrics.c: device_destroy(nvmf_class, MKDEV(0, 0)); drivers/nvme/host/fabrics.c: device_destroy(nvmf_class, MKDEV(0, 0)); drivers/nvme/host/fc.c: device_destroy(&fc_class, MKDEV(0, 0)); drivers/nvme/host/fc.c: device_destroy(&fc_class, MKDEV(0, 0)); drivers/nvme/target/fcloop.c: device_destroy(fcloop_class, MKDEV(0, 0)); drivers/platform/x86/wmi.c: device_destroy(&wmi_bus_class, MKDEV(0, 0)); drivers/platform/x86/wmi.c: device_destroy(&wmi_bus_class, MKDEV(0, 0)); drivers/staging/comedi/drivers/comedi_test.c: device_destroy(ctcls, MKDEV(0, 0)); drivers/staging/comedi/drivers/comedi_test.c: device_destroy(ctcls, MKDEV(0, 0)); drivers/video/fbdev/core/fbcon.c: device_destroy(fb_class, MKDEV(0, 0)); net/netfilter/xt_IDLETIMER.c: device_destroy(idletimer_tg_class, MKDEV(0, 0)); net/netfilter/xt_IDLETIMER.c: device_destroy(idletimer_tg_class, MKDEV(0, 0)); Note that most of these probably are not bugs. yet... But there is no reason to look up the device by dev_t for drivers allowing only one device anyway. Using device_unregister() directly makes the code easier to follow and prevents future bugs in case someone decides to support more devices. Maybe we should add a WARN_ON(!MAJOR(devt)) or similar to device_destroy() to prevent similar future problems? Bjørn
