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.liaskovi...@profitbricks.com>
> ---
> 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;
> }
>
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