imx_mu_isr() always calls pm_system_wakeup() even when it should not, making the system unable to enter sleep. Suspend fails as follows: armadillo:~# echo mem > /sys/power/state [ 2614.602432] PM: suspend entry (deep) [ 2614.610640] Filesystems sync: 0.004 seconds [ 2614.618016] Freezing user space processes ... (elapsed 0.001 seconds) done. [ 2614.626555] OOM killer disabled. [ 2614.629792] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. [ 2614.638456] printk: Suspending console(s) (use no_console_suspend to debug) [ 2614.649504] PM: Some devices failed to suspend, or early wake event detected [ 2614.730103] PM: resume devices took 0.080 seconds [ 2614.741924] OOM killer enabled. [ 2614.745073] Restarting tasks ... done. [ 2614.754532] PM: suspend exit ash: write error: Resource busy armadillo:~# Upstream commit 892cb524ae8a is correct, so this seems to be a mistake during cherry-pick. Cc: <stable@vger.kernel.org> Fixes: a16f5ae8ade1 ("mailbox: imx: fix wakeup failure from freeze mode") Signed-off-by: Daisuke Mizobuchi <mizo@atmark-techno.com> Reviewed-by: Dominique Martinet <dominique.martinet@atmark-techno.com> Reviewed-by: Peng Fan <peng.fan@nxp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>