On Mon, Nov 5, 2012 at 3:33 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > The xw9300 BIOS supplies _SEG methods that are incorrect, which results > in some LSI SCSI devices not being discovered. This adds a quirk to > ignore _SEG on this machine and default to zero. > > The xw9300 has three host bridges: > > ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-3f]) > ACPI: PCI Root Bridge [PCI1] (domain 0001 [bus 40-7f]) > ACPI: PCI Root Bridge [PCI2] (domain 0002 [bus 80-ff]) > > When the BIOS "ACPI Bus Segmentation" option is enabled (as it is by > default), the _SEG methods of the PCI1 and PCI2 bridges return 1 and 2, > respectively. However, the BIOS implementation appears to be incomplete, > and we can't enumerate devices in those domains. > > But if we assume PCI1 and PCI2 really lead to buses in domain 0, > everything works fine. Windows XP and Vista also seem to ignore > these _SEG methods. > > Reference: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=543308 > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=15362 > Reported-and-Tested-by: Sean M. Pappalardo <pegasus@xxxxxxxxxxxxxxxx> > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Sorry, I forgot to post this here. Speak up if you see any issues. I applied this to my pci/misc branch as v3.8 material. > --- > arch/x86/pci/acpi.c | 25 +++++++++++++++++++++++-- > 1 files changed, 23 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c > index 192397c..49e5195 100644 > --- a/arch/x86/pci/acpi.c > +++ b/arch/x86/pci/acpi.c > @@ -22,6 +22,7 @@ struct pci_root_info { > }; > > static bool pci_use_crs = true; > +static bool pci_ignore_seg = false; > > static int __init set_use_crs(const struct dmi_system_id *id) > { > @@ -35,7 +36,14 @@ static int __init set_nouse_crs(const struct dmi_system_id *id) > return 0; > } > > -static const struct dmi_system_id pci_use_crs_table[] __initconst = { > +static int __init set_ignore_seg(const struct dmi_system_id *id) > +{ > + printk(KERN_INFO "PCI: %s detected: ignoring ACPI _SEG\n", id->ident); > + pci_ignore_seg = true; > + return 0; > +} > + > +static const struct dmi_system_id pci_crs_quirks[] __initconst = { > /* http://bugzilla.kernel.org/show_bug.cgi?id=14183 */ > { > .callback = set_use_crs, > @@ -98,6 +106,16 @@ static const struct dmi_system_id pci_use_crs_table[] __initconst = { > DMI_MATCH(DMI_BIOS_VERSION, "6JET85WW (1.43 )"), > }, > }, > + > + /* https://bugzilla.kernel.org/show_bug.cgi?id=15362 */ > + { > + .callback = set_ignore_seg, > + .ident = "HP xw9300", > + .matches = { > + DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), > + DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9300 Workstation"), > + }, > + }, > {} > }; > > @@ -108,7 +126,7 @@ void __init pci_acpi_crs_quirks(void) > if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) && year < 2008) > pci_use_crs = false; > > - dmi_check_system(pci_use_crs_table); > + dmi_check_system(pci_crs_quirks); > > /* > * If the user specifies "pci=use_crs" or "pci=nocrs" explicitly, that > @@ -455,6 +473,9 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root) > int pxm; > #endif > > + if (pci_ignore_seg) > + domain = 0; > + > if (domain && !pci_domains_supported) { > printk(KERN_WARNING "pci_bus %04x:%02x: " > "ignored (multiple domains not supported)\n", > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
