Re: [PATCH 4/5] platform/x86: x86-android-tablets: Workaround Lenovo Yoga Tablet 2 830/1050 poweroff hang

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Thu, Feb 24, 2022 at 05:57:11PM +0100, Hans de Goede wrote:
> Hi,
> 
> On 2/23/22 15:58, Andy Shevchenko wrote:
> > On Wed, Feb 23, 2022 at 02:31:52PM +0100, Hans de Goede wrote:
> >> These tablets' DSDT does not set acpi_gbl_reduced_hardware, so
> >> acpi_power_off gets used as pm_power_off handler. This causes "poweroff"
> >> on these tablets to hang hard. Requiring pressing the powerbutton for
> >> 30 seconds *twice* followed by a normal 3 second press to recover.
> >>
> >> Avoid this by overriding the global pm_power_off handler to do
> >> an EFI poweroff instead.
> > 
> > Oh, you eventually found the root cause (reduced HW bit)?
> 
> I'm not sure, it is possible that not setting the reduced HW bit
> is actually correct for this hw, but that does lead to using
> acpi_power_off which seems broken on this system.
> 
> I've updated the commit message while merging this to reflect
> that using acpi_power_off is the problem, rather then not setting
> the reduced HW bit.

Understood. Thanks!

> Also note that the issue of reboot being the same as poweroff once
> the system has been rebooted at least once is still unresolved.

-- 
With Best Regards,
Andy Shevchenko