At 2012/11/24 1:50, Vasilis Liaskovitis Wrote: > Offlining and removal of memory is now done in the prepare_remove callback, > not in the remove callback. > > The prepare_remove callback will be called when trying to remove a memory device > with the following ways: > > 1. send eject request by SCI > 2. echo 1>/sys/bus/pci/devices/PNP0C80:XX/eject > > Note that unbinding the acpi driver from a memory device with: > echo "PNP0C80:XX"> /sys/bus/acpi/drivers/acpi_memhotplug/unbind > > will no longer try to remove the memory. This is in compliance with normal > unbind driver core semantics, see the discussion in v2 of this patchset: > https://lkml.org/lkml/2012/11/16/649 If we don't remove it when unbinding it, it may cause kernel panicked. I have explained in another mail. Thanks Wen Congyang > > After a successful unbind of the driver: > - OSPM ejects of the memory device cannot proceed, as acpi_eject_store will > return -ENODEV on missing driver. > - SCI ejects of the memory device also cannot proceed, as they will also get > a "driver data is NULL" error. > So the memory can continue to be used safely after unbind. > > Signed-off-by: Vasilis Liaskovitis<vasilis.liaskovitis@xxxxxxxxxxxxxxxx> > --- > drivers/acpi/acpi_memhotplug.c | 18 ++++++++++++++++-- > 1 files changed, 16 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c > index eb30e5a..d0cfbd9 100644 > --- a/drivers/acpi/acpi_memhotplug.c > +++ b/drivers/acpi/acpi_memhotplug.c > @@ -55,6 +55,7 @@ MODULE_LICENSE("GPL"); > > static int acpi_memory_device_add(struct acpi_device *device); > static int acpi_memory_device_remove(struct acpi_device *device, int type); > +static int acpi_memory_device_prepare_remove(struct acpi_device *device); > > static const struct acpi_device_id memory_device_ids[] = { > {ACPI_MEMORY_DEVICE_HID, 0}, > @@ -69,6 +70,7 @@ static struct acpi_driver acpi_memory_device_driver = { > .ops = { > .add = acpi_memory_device_add, > .remove = acpi_memory_device_remove, > + .prepare_remove = acpi_memory_device_prepare_remove, > }, > }; > > @@ -448,6 +450,20 @@ static int acpi_memory_device_add(struct acpi_device *device) > static int acpi_memory_device_remove(struct acpi_device *device, int type) > { > struct acpi_memory_device *mem_device = NULL; > + > + if (!device || !acpi_driver_data(device)) > + return -EINVAL; > + > + mem_device = acpi_driver_data(device); > + > + acpi_memory_device_free(mem_device); > + > + return 0; > +} > + > +static int acpi_memory_device_prepare_remove(struct acpi_device *device) > +{ > + struct acpi_memory_device *mem_device = NULL; > int result; > > if (!device || !acpi_driver_data(device)) > @@ -459,8 +475,6 @@ static int acpi_memory_device_remove(struct acpi_device *device, int type) > if (result) > return result; > > - acpi_memory_device_free(mem_device); > - > return 0; > } > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>