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Date:   Thu, 14 Apr 2022 12:56:38 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     "Limonciello, Mario" <Mario.Limonciello@amd.com>
Cc:     "stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: Fix issues caused by lack of x86 LPI support
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On Tue, Apr 12, 2022 at 10:09:30PM +0000, Limonciello, Mario wrote:
> [Public]
> 
> Hi,
> 
> There are a variety of x86 systems that advertise LPI support and as part of negotiation with firmware they don't end up using C-states
> in certain circumstances.  This leads to higher runtime power consumption and also failure to enter s2idle. 
> 
> In mainline there have been changes to block that behavior.  Can you please backport these two commits from mainline?
> commit 01f6c7338ce267959975da65d86ba34f44d54220 ("cpuidle: PSCI: Move the `has_lpi` check to the beginning of the function")
> commit eb087f305919ee8169ad65665610313e74260463 ("ACPI: processor idle: Check for architectural support for LPI")
> 
> This should go to 5.15.y and later stable kernels.

Queued for 5.4 and newer kernels.  If you want this backported to older
ones, please provide a working set of patches.

thanks,

greg k-h