> -----Original Message----- > From: linux-acpi-owner@xxxxxxxxxxxxxxx [mailto:linux-acpi- > owner@xxxxxxxxxxxxxxx] On Behalf Of Rafael J. Wysocki > Sent: Wednesday, November 29, 2017 10:35 PM > To: Len Brown <lenb@xxxxxxxxxx> > Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>; linux acpi <linux- > acpi@xxxxxxxxxxxxxxx> > Subject: Re: Dell XPS13 9360 - 1,000ms acpi_pm_finish() > > On Wed, Nov 29, 2017 at 7:06 AM, Len Brown <lenb@xxxxxxxxxx> wrote: > > Rafael, > > > > Per our discussion... > > > > As of Linux-4.14, acpi_pm_finish() takes over 1,000 ms on the Dell > > XPS13. This routine accounts for 50% of the total resume time of this > > machine. > > > > So I commented _WAK out of acpi_hw_legacy_wake(), and that 1000ms > > became 2ms. (and the system also seemed to resume fine without _WAK, > > though I didn't test it extensively) > > How long does acpi_pm_finish() take in 4.12 kernel? It's good to know how much the reverted EC busy_polling mechanism can improve on this case. Thanks, rui > > So I effectively pre-pended acpi_pm_finish() to acpi_pm_end() with the > > hack patch below, and that seems to work fine. > > > > (Note that it seems that the relative ordering of enabling run-time > > GPEs and invoking _WAK is already correct in acpi_hw_legacy_wake() -- > > the GPEs are enabled first.) > > The ordering is correct, but the GPEs should be enabled before the SCI is > enabled by resume_device_irqs(). Arguably, they may just be enabled as > soon as the kernel gets control back as the SCI won't trigger anyway before > resume_device_irqs(). > > > So the question becomes... How early does _WAK really need to be? > > On this system, apparently, it may go late in the resume path. There are > systems on which moving it after the PCI resume introduced issues, which is > why the default ordering is what it is IIRC (but that was bundled with the GPE > stuff then, so there could be effects of that too). > > In any case, we may play with the ordering, but that's fragile. Or we can > enable the EC polling just for the time of executing _WAK (which should > avoid the thermal issues on Lenovo and similar). > > Thanks, > Rafael > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the > body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at > http://vger.kernel.org/majordomo-info.html ��.n��������+%������w��{.n�����{�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
