From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Young Subject: Re: kernel boot fail with efi earlyprintk (bisected) Date: Mon, 25 Aug 2014 14:07:13 +0800 Message-ID: <20140825060713.GA4011@darkstar.nay.redhat.com> References: <20140819081658.GA1795@darkstar.nay.redhat.com> <20140821205224.GJ29733@console-pimps.org> <20140822100258.GA1877@darkstar.nay.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20140822100258.GA1877-4/PLUo9XfK+sDdueE5tM26fLeoKvNuZc@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Matt Fleming Cc: lv.zheng-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, matt.fleming-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devel-E0kO6a4B6psdnm+yROfE0A@public.gmane.org, lenb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, rafael.j.wysocki-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, robert.moore-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org List-Id: linux-acpi@vger.kernel.org On 08/22/14 at 06:02pm, Dave Young wrote: > On 08/21/14 at 09:52pm, Matt Fleming wrote: > > On Tue, 19 Aug, at 04:16:58PM, Dave Young wrote: > > > Hi, > > > > > > 3.16 kernel boot fail with earlyprintk=efi on my laptop. > > > It keeps scrolling at the bottom line of screen. > > > > > > Bisected, the first bad commit is below: > > > commit 86dfc6f339886559d80ee0d4bd20fe5ee90450f0 > > > Author: Lv Zheng > > > Date: Fri Apr 4 12:38:57 2014 +0800 > > > > > > ACPICA: Tables: Fix table checksums verification before installation. > > > > > > > > > I did some debugging by enabling both serial and efi earlyprintk, below is > > > some debug dmesg, seems early_ioremap fails in scroll up function due to > > > no free slot, but I'm still not sure if the debug info is right or not. > > > > Thanks Dave, your callstack seems to make sense. > > > > Can you also enable early_ioremap_debug so that we can figure out where > > all the FIXMAP slots are going? > > With early_ioremap_debug enabled, there will be a lot of "dropped printk", so > I can not get any useful information. > > Will try to do more debug. early_ioremap_debug does not work because we are debugging early_printk but early_ioremap_debug itself will print warning message at the same time. Tried what Lv mentioned, increasing the early ioremap slots does help. Thanks Dave