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Date: Tue, 21 Jun 2016 10:58:33 +0300
From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Lv Zheng <lv.zheng@intel.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Len Brown <len.brown@intel.com>, Lv Zheng <zetalog@gmail.com>,
        linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org
Subject: Re: [PATCH v4 1/5] ACPICA: Namespace: Fix a regression that MLC
 support triggers dead lock in dynamic table loading
Message-ID: <20160621075833.GU1739@lahna.fi.intel.com>
References: <0e65135af51d94db0410c7059f3bc3a2300fc3b5>
 <cover.1466479787.git.lv.zheng@intel.com>
 <6cce63a111c40ca70552b003ef5a70eb239afd6f.1466479787.git.lv.zheng@intel.com>
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On Tue, Jun 21, 2016 at 12:34:15PM +0800, Lv Zheng wrote:
> The new MLC approach invokes MLC per-table basis. But the dynamic loading
> support of this is incorrect because of the lock order:
>  acpi_ns_evaluate
>    acpi_ex_enter_intperter
>      acpi_ns_load_table (triggered by Load opcode)
>        acpi_ns_exec_module_code_list
>          acpi_ex_enter_intperter
> The regression is introduced by the following commit:
>   Commit: 2785ce8d0da1cac9d8f78615e116cf929e9a9123
>   ACPICA Commit: 071eff738c59eda1792ac24b3b688b61691d7e7c
>   Subject: ACPICA: Add per-table execution of module-level code
> This patch fixes this regression by unlocking the interpreter lock before
> invoking MLC. However the unlocking is done to the acpi_ns_load_table(), in
> which, the interpreter lock should be locked by acpi_ns_parse_table() but
> wasn't. Reported by Mika Westerberg. Fixed by Lv Zheng.
> 
> Fixes: 2785ce8d0da1 ("ACPICA: Add per-table execution of module-level code")
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Now builds fine and fixes the hang, thanks :)

Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>