提交 e399037e 编写于 作者: A Aaron Lu 提交者: Rafael J. Wysocki

ACPI / scan: set status to 0 if _STA failed

Some ACPI node's _STA will touch operation region field, since the
evaluation of _STA in acpi_bus_type_and_status is very early, the
operation region handler is not ready yet. Instead of fail that function
and not creating the acpi_device node consequently, set status to 0 so
that later when the driver for that device is probing, it can find
the acpi_device node and proceed normally. And at that time, the
handler for the operation region is ready and its _STA evaluation will
succeed, its present status can be checked there.

Even there will be no driver using this node later, it doesn't seem
hurt to have one more acpi_device node created with status set to 0.

This happens on Microsoft Surface 3, where the SPI device node NTRG's
_STA touches GPIO fields and the SPI core driver will only enumerate SPI
devices from ACPI if the acpi_device node is 1: created; 2: _STA
indicates it's present.

Note that due to another problem in SPI driver, for NTRG to be actually
enumerated, some changes have to be made in the SPI layer, which is
addressed by Mika(not send out yet):
https://bugzilla.kernel.org/show_bug.cgi?id=104291#c23

Link: https://bugzilla.kernel.org/show_bug.cgi?id=104291Reported-by: NBastien Nocera <bugzilla@hadess.net>
Signed-off-by: NAaron Lu <aaron.lu@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
上级 31ade3b8
......@@ -1461,7 +1461,7 @@ static int acpi_bus_type_and_status(acpi_handle handle, int *type,
*type = ACPI_BUS_TYPE_DEVICE;
status = acpi_bus_get_status_handle(handle, sta);
if (ACPI_FAILURE(status))
return -ENODEV;
*sta = 0;
break;
case ACPI_TYPE_PROCESSOR:
*type = ACPI_BUS_TYPE_PROCESSOR;
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册