Hi,

> From: Deak, Imre
> Subject: 4.9-rc1: [TMP_] ACPI namespace lookup failure, AE_ALREADY_EXISTS
> 
> Hi,
> 
> after upgrading to 4.9-rc1 I get the following errors occasionally
> during boot and suspend-to-ram on an APL system:
> 
> [   59.513434] ACPI Error: [TMP_] Namespace lookup failure, AE_ALREADY_EXISTS (20160831/dswload2-330)
> [   59.513446] ACPI Exception: AE_ALREADY_EXISTS, During name lookup/catalog (20160831/psobject-227)
> [   59.513469] ACPI Error: Method parse/execution failed [\_SB.PCI0.SCPG] (Node ffff8802770b7bb8),
> AE_ALREADY_EXISTS (20160831/psparse-543)
> [   59.515415] ACPI Error: Method parse/execution failed [\_SB.PCI0.SDHA._PS3] (Node ffff8802770b7dc0),
> AE_ALREADY_EXISTS (20160831/psparse-543)
> [   59.517118] ACPI: Marking method _PS3 as Serialized because of AE_ALREADY_EXISTS error
> 
> Other than these error messages, booting and suspend/resume seems to work ok.
> Bisecting points to
> commit 74f51b80a0c4ff84fbeb7f12ea43ce66934d29aa
> Author: Lv Zheng <lv.zheng@intel.com>
> Date:   Wed Sep 7 14:07:10 2016 +0800
> 
>     ACPICA: Namespace: Fix dynamic table loading issues
> 
> Reverting this on top of 4.9-rc1 gets rid of the error messages.

The commit in question only modified code to make locks unlocked/locked.
Which should be transparent to the functional stuffs.
I'm not sure how it can lead to such error in the single-threading boot environment.
Please provide the acpidump output for further investigation.

Thanks and best regards
Lv