lkml.org 
[lkml]   [2018]   [Jan]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [BISECTED] v4.15-rc: Boot regression on x86_64/AMD
    Hi,

    On Fri, Jan 05, 2018 at 04:00:25PM -0800, Linus Torvalds wrote:
    > On Fri, Jan 5, 2018 at 2:04 PM, Aaro Koskinen <aaro.koskinen@iki.fi> wrote:
    > > After v4.14, I've been unable to boot my AMD compilation box with the
    > > v4.15-rc mainline Linux. It just ends up in a silent reboot loop.
    > >
    > > I bisected this to:
    > >
    > > commit fa564ad9636651fd11ec2c79c48dee844066f73a
    > > Author: Christian König <christian.koenig@amd.com>
    > > Date: Tue Oct 24 14:40:29 2017 -0500
    > >
    > > x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 00-1f, 30-3f, 60-7f)
    >
    > Hmm. That was reported to break boot earlier already.
    >
    > The breakage was supposedly fixed by three patches from Christian:
    >
    > a19e2696135e: "x86/PCI: Only enable a 64bit BAR on single-socket AMD
    > Family 15h"
    >
    > 470195f82e4e: "x86/PCI: Fix infinite loop in search for 64bit BAR placement"
    >
    > and a third one that was apparently never applied.
    >
    > I'm not sure why that third patch was never applied, I'm including it here.
    >
    > Does the system work for you if you apply that patch (instead of
    > reverting all of them)?

    Yes, I think it now works.

    When booting with kexec from v4.14:
    89876f275e8d562912d9c238cd888b52065cf25c alone ==> boot fails.
    89876f275e8d562912d9c238cd888b52065cf25c and the patch ==> boot OK.

    However, I noticed I cannot do multiple kexecs in a row - it works only
    once, and the second one just silently fails/reboots the CPU regardless
    what the kernel is. But this behaviour is already the same with v4.14. :-/

    A.

    > I wonder why that patch wasn't applied, but if it doesn't fix things,
    > I think we do need to revert it all.
    >
    > Christian? Bjorn?
    >
    > Linus

    > From e5d5c9682aa02a6b9c0c6bd446d433b924441679 Mon Sep 17 00:00:00 2001
    > From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
    > Date: Tue, 28 Nov 2017 10:02:35 +0100
    > Subject: [PATCH 3/3] x86/PCI: limit the size of the 64bit BAR to 256GB
    > MIME-Version: 1.0
    > Content-Type: text/plain; charset=UTF-8
    > Content-Transfer-Encoding: 8bit
    >
    > This avoids problems with Xen which hides some memory resources from the
    > OS and potentially also allows memory hotplug while this fixup is
    > enabled.
    >
    > Signed-off-by: Christian König <christian.koenig@amd.com>
    > ---
    > arch/x86/pci/fixup.c | 2 +-
    > 1 file changed, 1 insertion(+), 1 deletion(-)
    >
    > diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
    > index c817ab85dc82..149adbc7f2a3 100644
    > --- a/arch/x86/pci/fixup.c
    > +++ b/arch/x86/pci/fixup.c
    > @@ -701,7 +701,7 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev)
    > res->name = "PCI Bus 0000:00";
    > res->flags = IORESOURCE_PREFETCH | IORESOURCE_MEM |
    > IORESOURCE_MEM_64 | IORESOURCE_WINDOW;
    > - res->start = 0x100000000ull;
    > + res->start = 0xbd00000000ull;
    > res->end = 0xfd00000000ull - 1;
    >
    > /* Just grab the free area behind system memory for this */
    > --
    > 2.11.0
    >

    \
     
     \ /
      Last update: 2018-01-06 03:11    [W:2.271 / U:0.032 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site