2012/11/15 15:59, Wen Congyang wrote:
> If the memory device is hotplugged before the driver is loaded, the user
> cannot see this device under the directory /sys/bus/acpi/devices/, and the
> user cannot bind it by hand after the driver is loaded. This patch
> introduces a new feature to bind such device when the driver is being
> loaded.
>
> CC: David Rientjes <rientjes@xxxxxxxxxx>
> CC: Jiang Liu <liuj97@xxxxxxxxx>
> CC: Len Brown <len.brown@xxxxxxxxx>
> CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> CC: Paul Mackerras <paulus@xxxxxxxxx>
> CC: Christoph Lameter <cl@xxxxxxxxx>
> Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
> CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> CC: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
> CC: Rafael J. Wysocki <rjw@xxxxxxx>
> CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
> ---
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Thanks,
Yasuaki Ishimatsu
> drivers/acpi/acpi_memhotplug.c | 37 ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 36 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> index e0f7425..9f1d107 100644
> --- a/drivers/acpi/acpi_memhotplug.c
> +++ b/drivers/acpi/acpi_memhotplug.c
> @@ -52,6 +52,9 @@ MODULE_LICENSE("GPL");
> #define MEMORY_POWER_ON_STATE 1
> #define MEMORY_POWER_OFF_STATE 2
>
> +static bool auto_probe;
> +module_param(auto_probe, bool, S_IRUGO | S_IWUSR);
> +
> static int acpi_memory_device_add(struct acpi_device *device);
> static int acpi_memory_device_remove(struct acpi_device *device, int type);
>
> @@ -494,12 +497,44 @@ acpi_memory_register_notify_handler(acpi_handle handle,
> u32 level, void *ctxt, void **retv)
> {
> acpi_status status;
> -
> + struct acpi_memory_device *mem_device = NULL;
> + unsigned long long current_status;
>
> status = is_memory_device(handle);
> if (ACPI_FAILURE(status))
> return AE_OK; /* continue */
>
> + if (auto_probe) {
> + /* Get device present/absent information from the _STA */
> + status = acpi_evaluate_integer(handle, "_STA", NULL,
> + ¤t_status);
> + if (ACPI_FAILURE(status))
> + goto install;
> +
> + /*
> + * Check for device status. Device should be
> + * present/enabled/functioning.
> + */
> + if (!(current_status &
> + (ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
> + ACPI_STA_DEVICE_FUNCTIONING)))
> + goto install;
> +
> + if (acpi_memory_get_device(handle, &mem_device))
> + goto install;
> +
> + /* We have bound this device while we register the driver */
> + if (mem_device->state == MEMORY_POWER_ON_STATE)
> + goto install;
> +
> + ACPI_DEBUG_PRINT((ACPI_DB_INFO,
> + "\nauto probe memory device\n"));
> +
> + if (acpi_memory_enable_device(mem_device))
> + pr_err(PREFIX "Cannot enable memory device\n");
> + }
> +
> +install:
> status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
> acpi_memory_device_notify, NULL);
> /* continue */
>
--
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