On Thu, 2009-04-09 at 15:06 +0300, Maxim Levitsky wrote: > On Tue, 2009-04-07 at 17:24 +0200, Rafael J. Wysocki wrote: > > On Tuesday 07 April 2009, Maxim Levitsky wrote: > > > Hi, > > > > Hi, > > > > > This is first time, I am actually happy about a regression.... > > > > > > I have a notebook, aspire 5720G that fails to do two suspends to ram in > > > row. > > > > > > for example I can do s2ram->s2disk->s2ram->... > > > but can't s2ram->s2ram. > > > > > > Well that at least was the situation till now. > > > Also there is no way to debug this - bios doesn't pass control back to > > > linux on failed resume. I tried probably every guess I could come with. > > > > > > Now, after a commit a0d4922da2e4ccb0973095d8d29f36f6b1b5f703 which I > > > finally bisected, I can't anymore do two suspends to ram at all, > > > regardless of suspend to disk in between. Also bios doesn't pass control > > > when resume fails. > > > > I wonder what happens if the in-between s2disk is in the "shutdown" mode. > > Theoretically, it should work as a cold boot, so the second s2ram should work > > in this case. > > > > > I actually did 3 bisects, as I had to find fixes to 2 more s2ram bugs > > > that were fixed. > > > the fixes are: > > > > > > a0e280e0f33f6c859a235fb69a875ed8f3420388 > > > 1e70c7f7a9d4a3d2cc78b40e1d7768d99cd79899 > > > > Commit a0d4922da2e4ccb0973095d8d29f36f6b1b5f703 has been modified quite a bit > > by some later commits due to regressions it introduced. > > > > > Now, why I am happy about this: > > > It seems that a suspend cycle changes something that explodes on next > > > resume. a s2disk cycle cleared this, but not anymore, thus the poison > > > must be somehow connected to the > > > a0d4922da2e4ccb0973095d8d29f36f6b1b5f703 > > > > Hint: it would be a lot easier to read the message if you included the subjects > > of the commits too. :-) > > > Sure, sorry ;-) > > > > PCI state?? I tried restoring it from saved file, (created on suspend) > > > but this didn't help. > > > (Only a single register, which looks like a clear or write register > > > changed). > > > > > > > > > Also this commits narrows down the search, now it is clear that this is > > > usb related. No wonder bios pokes at usb on resume and stalls..... > > > > > > > > > It could even be connected to bios handoff, maybe we don't do that on > > > resume? > > > > > > (Note: this regression is present all way to latest -git) > > > > I'm not sure if we really should consider this as a regression. s2ram clearly > > didn't work correctly on your machine before and the s2disk in between > > is not really relevant here IMO. > Yet, this allowed me at least lalf the time to do s2ram. > s2disk eats battery, if I suspend the system for short time > > > > > > > What do you think? > > > > Well, not much apart from the observation that the problem with s2ram on your > > machine is probably related to USB. In fact, on Intel chipsets there seem to > > be some strange links between the USB controllers (most notably EHCI) and > > the core chipset that don't appear to be well documented and this may be the > > case in which they show up. Dunno. > > Sorry for late reply, > > I now semi-bisected, the change inside this patch. > > First, UHCI doesn't affect anything. > > Then, if I move 'late' suspend functions inside normal ones, everything > returns works like it used to be (I need to retest this statement, I did > other changes too). Yep, just moving content of late suspend and content of early resume to normal suspend/resume functions fixes this issue. > > > Also, I got a idea about, think about this: > my notebook has a webcam, a usb UVC webcam. > > Fact that it has firmware, can't be argued, it has to be true. > Suppose its firmware is stored in bios? > In this case, bios would load it on resume from ram, thus it will need > fully functional ehci controller. > We do something wrong, or more correctly, bios has some wrong > assumptions (read assume windows driver) about ehci state. > > > Best regards, > Maxim Levitsky > > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
