On Thursday, 1 November 2007 16:25, Maxim Levitsky wrote: > On Tuesday 30 October 2007 01:31:13 Rafael J. Wysocki wrote: > > On Monday, 29 October 2007 23:36, Maxim Levitsky wrote: > > > On Monday 29 October 2007 22:37:37 Rafael J. Wysocki wrote: > > > > On Monday, 29 October 2007 07:45, Maxim Levitsky wrote: > > > > > On Sunday 28 October 2007 22:23:15 Rafael J. Wysocki wrote: > > > > > > On Sunday, 28 October 2007 21:00, Maxim Levitsky wrote: > > > > > > > On Saturday 27 October 2007 23:46:45 Rafael J. Wysocki wrote: > > > > > > > > On Saturday, 27 October 2007 14:05, Maxim Levitsky wrote: > > > > > > > > > Hi, > > > > > > > > > > > > > > > > > > Recently I noticed that my system resumes just after suspend to disk. > > > > > > > > > > > > > > > > > > I traced this to commit 9cd9a0058dd35268b24fa16795a92c800f4086d4. > > > > > > > > > > > > > > > > > > Note: > > > > > > > > > > > > > > > > > > This happens only if I enable WOL using /proc/acpi/wakeup > > > > > > > > > (echo "ILAN" > /proc/acpi/wakeup) > > > > > > > > > > > > > > > > What happens after a suspend to RAM? > > > > > > > I do more testing tomorrow, but what I remember is that, > > > > > > > I had no issues with suspend-to-ram. > > > > > > > (And take into account the fact that _all_ wakeup devices were enabled always, > > > > > > > the rc.local does that for me, and still I did quite a lot of suspends, but I > > > > > > > got the immediate resume, only and always after suspend to disk. > > > > > > > > > > > > Hm, can you please retest with the above commit applied, but with > > > > > > device_suspend() in hibernation_platform_enter() replaced by device_shutdown()? > > > > > Bingo! doing the above fixes this problem. > > > > > And... strange, since I did test the system with e1000 unloaded, but still got same bug, > > > > > back when I chased that bug, thus it is probably not related to e1000 and WOL. > > > > > > > > > > the ACPI wake-up source (I have read the DSDT, and ICH datasheets, thus I know that this is a set of bits in southbridge) > > > > > of e1000 is shared with EHCI and HDA sound codec. > > > > > (But usb on my system only able to wake from S3, and the soundchip which can theoretically wake up from S3 too, doesn't have this ability) > > > > > > > > > > (But disabling this wakeup source, fixes this bug too) > > > > > > > > OK > > > > > > > > Please get back to device_suspend() in hibernation_platform_enter() and try > > > > to unload ehci_hcd before hibernation with the wakeup source enabled. > > > Well, ... bingo! again! > > > > > > Replacing back the device_suspend() , and unloading the ehci_hcd fixes the problem! > > > Even more, loading this module back causes this problem to reappear, and vise-verso. > > > All wakeup sources are enabled always. > > > > > > Note that I don't have any USB 2.0 devices yet. > > > The usb devices I have are: keyboard,mouse,and joystick. > > > > > > So now this problem looks fixable, I take a look at ehci driver. > > > > This is very similar to what I've been observing for some time on one of my > > test boxes wrt suspending to RAM and in that case the problem is also related > > to EHCI (this is a pretty old Celeron-based box with an Intel chipset). > > > > It looks like in some situations, on some platforms the EHCI controller > > triggers a resume right after the suspend (or hibernation) if the driver's > > .suspend() routine is executed before invoking the ACPI firmware to put the > > system into the sleep state. > > > > [The "ehci_hcd causes box to resume immediately after suspend to RAM" thread on > > linux-pm was about this problem.] > > > > Greetings, > > Rafael > > > > Sorry, for a bit late response, > > Do you meant that EHCI driver triggers the resume regardless of the above commit? Rather, the hardware does it, but the driver is at least partially involved (ie. unloading ehci-hcd before a suspend to RAM makes the box behave as expected, which is to stay suspended). > Now I have checked the source and understand that the above commit is 150% right. > (Actually I always assumed that it was always there, and some developers did that too) > > > I assumed that on hibernation the sequence is: > > .suspend() - disable device + enable wake > snapshot > > .resume() - enabled device + disable wake > snapshot writeout > .suspend() - disable device + enable wake > > > But before the above commit was introduced, the last .suspend() > didn't happen, and thus all the code that enables wake was disabled. > For the same reason rtc-cmos didn't work, since its .resume disables the alarm. Yes. > The mystery why my system did react to WOL in S4 is resolved by the fact that > e1000 .shutdown() calls .suspend() to make WOL work in S5 too. > (Btw, this is wrong that rtc-cmos disables alarm in .shutdown() since it can be used in S5 too) > > > So, this commit caused the EHCI .suspend to activate the wakeup, and this code probably contains a bug > (Or a lack of hardware workaround) I bet on the lack of hardware workaround in there. Also, the problem seems to be related to the sharing of resources between EHCI and some devices (sharing interrupts, wakeup sources). > Thus, since the suspend to ram isn't affected by the above commit, I want to know > whenever it affects the system you have seen resuming from ram instantly with ehci driver. No it doesn't, AFAICS. I tested this patch on the affected system before posting it. Greetings, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
