lkml.org 
[lkml]   [2009]   [Apr]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] x86/pci: do assign root bus res if _CRS is used
    On Mon, Apr 27, 2009 at 01:44:01PM -0600, Bjorn Helgaas wrote:
    > On Monday 20 April 2009 07:35:40 pm Yinghai Lu wrote:
    > > it wil be overwriten later if _CRS is used, so don't bother to set it.
    > >
    > > [ Impact: cleanup ]
    > >
    > > Signed-off-by: Yinghai Lu <yinghai@kernel.org>
    > >
    > > ---
    > > arch/x86/pci/amd_bus.c | 4 ++++
    > > 1 file changed, 4 insertions(+)
    > >
    > > Index: linux-2.6/arch/x86/pci/amd_bus.c
    > > ===================================================================
    > > --- linux-2.6.orig/arch/x86/pci/amd_bus.c
    > > +++ linux-2.6/arch/x86/pci/amd_bus.c
    > > @@ -100,6 +100,10 @@ void x86_pci_root_bus_res_quirks(struct
    > > int j;
    > > struct pci_root_info *info;
    > >
    > > + /* don't go for it if _CRS is used */
    > > + if (pci_probe & PCI_USE__CRS)
    > > + return;
    > > +
    > > /* if only one root bus, don't need to anything */
    > > if (pci_root_num < 2)
    > > return;
    >
    > This isn't a comment on this patch per se.
    >
    > I am concerned about the fact that "pci=use_crs" is not the default.
    > >From the changelog of 62f420f8282, it sounds like you have to boot an
    > IBM x3850 with "pci=use_crs" to make hot-plug work, even though ACPI
    > tells us everything we need to know. That's backwards.
    >
    > We shouldn't need an option to tell Linux that the firmware is
    > trustworthy. We should have an option to *ignore* it for the times
    > when we trip over something broken and haven't figured out a way to
    > work around it yet.

    Sorry, I am behind on my email and just noticed this.

    When I posted the patches to add "pci=use_crs" it was only
    needed to enable PCI hotplug on a subset of our systems.
    At that time it was not apparent that others were interested.
    I was also concerned that real or anticipated breakage on
    on other systems might delay or prevent acceptance.

    As long as there is an option to disable it I am also in
    favor of trying to make it the default.

    Thanks!

    Gary

    --
    Gary Hade
    System x Enablement
    IBM Linux Technology Center
    503-578-4503 IBM T/L: 775-4503
    garyhade@us.ibm.com
    http://www.ibm.com/linux/ltc



    \
     
     \ /
      Last update: 2009-04-30 02:09    [W:0.024 / U:59.668 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site