On 22 May 2018 at 13:02, Rafael J. Wysocki <[email protected]> wrote: > From: Rafael J. Wysocki <[email protected]> > > Commit 08810a4119aa (PM / core: Add NEVER_SKIP and SMART_PREPARE > driver flags) inadvertently prevented the power.direct_complete flag > from being set for devices without PM callbacks and with disabled > runtime PM which also prevents power.direct_complete from being set > for their parents. That led to problems including a resume crash on > HP ZBook 14u. > > Restore the previous behavior by causing power.direct_complete to be > set for those devices again, but do that in a more direct way to > avoid overlooking that case in the future. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=199693 > Fixes: 08810a4119aa (PM / core: Add NEVER_SKIP and SMART_PREPARE driver flags) > Reported-by: Thomas Martitz <[email protected]> > Tested-by: Thomas Martitz <[email protected]> > Signed-off-by: Rafael J. Wysocki <[email protected]>
It seems like the resume path of HP ZBook 14u is kind of fragile, in case it *requires* dev->power.direct_complete to be set for devices like these. And that makes me wonder, that perhaps we should try to address that issue as well, no? In either way: Reviewed-by: Ulf Hansson <[email protected]> Kind regards Uffe > --- > drivers/base/power/main.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > Index: linux-pm/drivers/base/power/main.c > =================================================================== > --- linux-pm.orig/drivers/base/power/main.c > +++ linux-pm/drivers/base/power/main.c > @@ -1920,10 +1920,8 @@ static int device_prepare(struct device > > dev->power.wakeup_path = false; > > - if (dev->power.no_pm_callbacks) { > - ret = 1; /* Let device go direct_complete */ > + if (dev->power.no_pm_callbacks) > goto unlock; > - } > > if (dev->pm_domain) > callback = dev->pm_domain->ops.prepare; > @@ -1957,7 +1955,8 @@ unlock: > */ > spin_lock_irq(&dev->power.lock); > dev->power.direct_complete = state.event == PM_EVENT_SUSPEND && > - pm_runtime_suspended(dev) && ret > 0 && > + ((pm_runtime_suspended(dev) && ret > 0) || > + dev->power.no_pm_callbacks) && > !dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP); > spin_unlock_irq(&dev->power.lock); > return 0; >
