Re: [PATCH] xen: take system_transition_mutex on suspend

[Mario Limonciello <superm1@xxxxxxxxxx>]

On 9/22/25 1:06 AM, Jürgen Groß wrote:
> On 21.09.25 18:28, Marek Marczykowski-Górecki wrote:
> > Xen's do_suspend() calls dpm_suspend_start() without taking required
> > system_transition_mutex. Since 12ffc3b1513eb moved the
> > pm_restrict_gfp_mask() call, not taking that mutex results in a WARN.
> >
> > Take the mutex in do_suspend(), and use mutex_trylock() to follow
> > how enter_state() does this.
> >
> > Suggested-by: Jürgen Groß <jgross@xxxxxxxx>
> > Fixes: 12ffc3b1513eb "PM: Restrict swap use to later in the suspend 
> > sequence"
> > Link: https://lore.kernel.org/xen-devel/aKiBJeqsYx_4Top5@mail-itl/
> > Signed-off-by: Marek Marczykowski-Górecki 
> > <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx # v6.16+
> Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
>
>
> Juergen
Reviewed-by: Mario Limonciello (AMD) <superm1@xxxxxxxxxx>