On Tue, Feb 26, 2013 at 12:14 PM, Artem S. Tashkinov <t.artem@xxxxxxxxx> wrote: > Feb 27, 2013 12:47:01 AM, Bjorn Helgaas wrote: > On Mon, Feb 25, 2013 at 11:35 PM, Artem S. Tashkinov wrote: >>> Feb 26, 2013 03:57:52 AM, Bjorn Helgaas wrote: >>>> >>>>Where are we at with this, Artem? I assume it's still a problem. >>>> >>> >>> Yes, it is, Bjorn. >>> >>> In order to eliminate this problem I switched back to MBR yesterday, because >>> so far I haven't received any instructions or guidance as to how I can debug >>> it further. I'm absolutely sure USB write speed is just another manifestation of >>> it so I decided not to debug USB specifically (it just doesn't make too much >>> sense). >>> >>> What I see is that something terribly wrong is going on but if Linus has no ideas >>> I, as an average Joe, don't have a slightest clue as to what I can do. >>> >>> The bug report with necessary, but seemingly useless information, can be >>> found here: https://bugzilla.kernel.org/show_bug.cgi?id=53551 >>> >>> If anyone comes up with new ideas I can quickly try UEFI again now that I >>> have two HDDs at my disposal (the old one is formatted as GPT, the new one is >>> MBR). >> >>The ideas I saw are: >> >>1) Figure out whether it ever worked. If an older kernel worked >>correctly and a newer one is broken, bisection is at least a >>possibility. You mentioned that it did work before (Feb 12), but in >>the past you never suspended twice in one boot session, whereas maybe >>you did when seeing the problem? > > This is difficult to say since the first kernel I tried to run in EUFI mode was > 3.7.x, so I've no idea if any previous ones ever worked. > >> >>2) Try the "setpci" to set the MSI address back to the original value >>to see if it makes a difference (see my Feb 12 message). > > I will try it soon and report back to you. > >> >>3) Collect "lspci -vvv -xxxx" output to investigate the XHCI >>Unsupported Request errors. >> >>4) Use usbmon to collect traces before and after the suspend. > > Likewise. Still I don't quite understand why you are persistent in your > desire to investigate USB controllers specifically - my problem affects > all storage devices that I have. Well, in the absence of good ideas about what's going on, I guess we have to pursue even the bad ideas that don't seem like they'd be related :) Speaking of bad ideas, any news on 2) and 3) above? You mentioned in the bugzilla that Windows complains about MTRRs being changed across the S4 sleep state transition. I don't think Linux looks for such a change. You could try looking at /proc/mtrr before and after the suspend/resume to see if anything changed there. It looks like there's even support for *writing* the MTRRs via /proc/mtrr, so if anything did change, you could also try changing it back. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
