Re: [PATCH 6.6 1/1] PM: sleep: Restore asynchronous device resume optimization

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Mon, Sep 02, 2024 at 05:32:48PM +0800, Yenchia Chen wrote:
> From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
> 
> commit 3e999770ac1c7c31a70685dd5b88e89473509e9c upstream.
> 
> Before commit 7839d0078e0d ("PM: sleep: Fix possible deadlocks in core
> system-wide PM code"), the resume of devices that were allowed to resume
> asynchronously was scheduled before starting the resume of the other
> devices, so the former did not have to wait for the latter unless
> functional dependencies were present.
> 
> Commit 7839d0078e0d removed that optimization in order to address a
> correctness issue, but it can be restored with the help of a new device
> power management flag, so do that now.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
> Signed-off-by: Yenchia Chen <yenchia.chen@mediatek.com>
> ---
>  drivers/base/power/main.c | 117 +++++++++++++++++++++-----------------
>  include/linux/pm.h        |   1 +
>  2 files changed, 65 insertions(+), 53 deletions(-)

Why does this need to be backported?  What bug is it fixing?

confused,

greg k-h