On Thu, Feb 23, 2017 at 07:40:13PM +0100, Pavel Machek wrote: > On Thu 2017-02-23 17:28:26, Frederic Weisbecker wrote: > > On Tue, Feb 14, 2017 at 08:27:43PM +0100, Pavel Machek wrote: > > > On Tue 2017-02-14 18:59:56, Pavel Machek wrote: > > > > Hi! > > > > > > > > > > > > Hmm. I moved keyboard between USB ports, and now 4.10-rc6 no longer > > > > > > > > boots. v4.6 works ok. Let me try with keyboard unplugged... no, I > > > > > > > > could not get it to work. I believe v4.9 and some v4.10-rc's worked, > > > > > > > > but I'll have to double check. > > > > > > > > > > > > > > But all the kernel versions worked when the keyboard was plugged into > > > > > > > its original USB port? > > > > > > > > > > > > Aha. So it looks difference is probably in "where is keyboard plugged > > > > > > in" but in "reboot" vs. "cold boot". I did not do a cold boot in quite > > > > > > a while :-(. > > > > > > > > > > > > Booting to grub, then hitting ctrl-alt-del is enough to make it work. Ouch. > > > > > > > > > > > > It happens with current Linus' tree. > > > > > > > > > > v4.10-rc6-feb3 : broken > > > > > v4.9 : ok > > > > > (v4.6 : ok) > > > > > > > > Hmm. It hangs during PCI fixups, and it hangs in v4.10-rc8, too. > > > > > > > > With debug patch below, I get > > > > > > > > ...1d.7: PCI fixup... pass 2 > > > > ...1d.7: PCI fixup... pass 3 > > > > ...1d.7: PCI fixup... pass 3 done > > > > > > > > ...followed by hang. So yes, it looks USB related. > > > > > > > > (Sometimes it hangs with some kind backtrace involving secondary CPU > > > > startup, unfortunately useful info is off screen at that point). > > > > > > Forgot to say, 1d.7 is EHCI controller. > > > > > > 00:1d.7 USB controller: Intel Corporation NM10/ICH7 Family USB2 EHCI > > > Controller (rev 01) > > > > Ok, I should have access soon to a EeePc 1015CX (which seem to have this controller). > > I hope I'll be able to reproduce the issue there. If not, I'm sorry but I'll have to > > burden you again :-) > > Go through more mails. It is only reproducible after cold boot. .. so > I doubt it will be easy to reproduce on another machine. > > Now... I do have serial port, and I even might have serial cable > somewhere, but.... Giving how sensitive it is, it is probably going to > go away with console on ttyS... So I had access to a machine with NM10/ICH7 chipset and I failed to reproduce. What machine is it you're using? I fear you're my last resort. I suspect something is programming the clockevent behind the tick. I thought it could be the clockevents switch code but I can't find any issue there. I see you have CONFIG_HIGH_RES_TIMERS=n. Could you try with it enabled? For a quick rewind: git reset --hard v4.10 git revert 558e8e27e73f53f8a512485be538b07115fe5f3c Thanks!