From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Prakash, Prashanth" <pprakash@codeaurora.org>
Subject: Re: [PATCH 1/3] ACPI: move ACPI_SYSTEM_HID to acpi_drivers.h
Date: Fri, 18 Mar 2016 09:33:38 -0600
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To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: ACPI Devel Maling List <linux-acpi@vger.kernel.org>, harba@codeaurora.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>, "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org>

Than

On 3/17/2016 3:54 PM, Rafael J. Wysocki wrote:
> On Thu, Mar 17, 2016 at 5:53 PM, Prakash, Prashanth
> <pprakash@codeaurora.org> wrote:
>> Hi Rafael,
>>
>> On 3/16/2016 7:50 PM, Rafael J. Wysocki wrote:
>>>  #include "internal.h"
>>> @@ -22,7 +24,6 @@ ACPI_MODULE_NAME("scan");
>>>  extern struct acpi_device *acpi_root;
>>>
>>>  #define ACPI_BUS_CLASS                 "system_bus"
>>> -#define ACPI_BUS_HID                   "LNXSYBUS"
>>> No.
>>>
>>> This is not a valid device ID and should never be used as such.
>> Section 5.6.6 in ACPI 6.1 is defining the notification value for the graceful
>> shutdown request as a ACPI device specific value(0x81) and it is targeting
>> the system bus(\_SB), so we took the current approach of creating a sybus
>> driver to handle the notifications targeting the system bus.
>>
>> Let me go through the code again and see if we can avoid using the
>> ACPI_BUS_HID.
> You can.
>
>> In the meantime, if you have any specific thoughts on
>> how this should be handled, please let us know.
> Your goal is relatively simple.  You want to register a notify handler
> for the \_SB object.  You don't need a driver for that, because the
> \_SB object is always present, so you don't need to enumerate it or
> wait for it to show up etc.
>
> I'd just scan the namespace 1 level below the root and install the
> handler for the object with the matching name (not a fake device ID).
Thanks Rafael! I will update the patch using the above approach.

-Prashanth
> Thanks,
> Rafael
>
>