From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754579AbdBNTzD (ORCPT ); Tue, 14 Feb 2017 14:55:03 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:59092 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754410AbdBNTyz (ORCPT ); Tue, 14 Feb 2017 14:54:55 -0500 Date: Tue, 14 Feb 2017 14:54:53 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Pavel Machek cc: torvalds@linux-foundation.org, kernel list , , , , Subject: Re: v4.10-rc8 (-rc6) boot regression on Intel desktop, does not boot after cold boots, boots after reboot In-Reply-To: <20170214192743.GA3869@amd> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 14 Feb 2017, 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) So this looks like a problem in the PCI subsystem affecting a USB controller. Linus is right; bisection is the best approach now that you know a reliable trigger. Alan Stern