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 <rient...@google.com> CC: Jiang Liu <liu...@gmail.com> CC: Len Brown <len.br...@intel.com> CC: Benjamin Herrenschmidt <b...@kernel.crashing.org> CC: Paul Mackerras <pau...@samba.org> CC: Christoph Lameter <c...@linux.com> Cc: Minchan Kim <minchan....@gmail.com> CC: Andrew Morton <a...@linux-foundation.org> CC: KOSAKI Motohiro <kosaki.motoh...@jp.fujitsu.com> CC: Yasuaki Ishimatsu <isimatu.yasu...@jp.fujitsu.com> CC: Rafael J. Wysocki <r...@sisk.pl> CC: Konrad Rzeszutek Wilk <konrad.w...@oracle.com> Signed-off-by: Wen Congyang <we...@cn.fujitsu.com> --- 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 8a8716f..24bfa6e 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); @@ -581,12 +584,44 @@ 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 */ -- 1.8.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/