| Message ID | 1373242613-4603-1-git-send-email-zhen-hual@hp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Sun, Jul 7, 2013 at 6:16 PM, Li, Zhen-Hua <zhen-hual@hp.com> wrote: > On some IA64 platforms with intel PCI bridge, for example, HP BL890c i2 > with Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port, > when kernel tries to disable the mmio decoding on the PCI bridge devices, > kernel may crash. > > And in the comment of function quirk_mmio_always_on, it also says: > "But doing so (disable the mmio decoding) may cause problems on host bridge > and perhaps other key system devices" > > So, for these PCI bridges, dev->mmio_always_on bit should be set to 1. > > > Signed-off-by: Li, Zhen-Hua <zhen-hual@hp.com> > --- > drivers/pci/quirks.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index e85d230..24b8024 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -44,6 +44,21 @@ static void quirk_mmio_always_on(struct pci_dev *dev) > DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_ANY_ID, PCI_ANY_ID, > PCI_CLASS_BRIDGE_HOST, 8, quirk_mmio_always_on); > > +#ifdef CONFIG_IA64 > +/* > + * On some IA64 platforms, for some intel PCI bridge devices, for example, > + * the Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port, > + * disable the mmio decoding on these devices may cause system crash. > + * So dev->mmio_always_on bit should be set to 1. > + */ > +static void quirk_mmio_on_intel_pcibridge(struct pci_dev *dev) > +{ > + dev->mmio_always_on = 1; > +} > +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_ANY_ID, PCI_ANY_ID, > + PCI_CLASS_BRIDGE_PCI, 8, quirk_mmio_on_intel_pcibridge); > +#endif The changelog and comment suggest an issue specific to Intel 5520/5500/X58, but the patch sets mmio_always_on for *all* PCI bridges. It claims to be specific to ia64 (and is only compiled there), but the chipset is also used for x86. You need to explain why the problem only affects ia64. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Bjorn, Thank you for reviewing this patch. I have created a new one and sent it out. And your questions are answered in that new wmail. Regards ZhenHua On 07/09/2013 04:35 AM, Bjorn Helgaas wrote: > On Sun, Jul 7, 2013 at 6:16 PM, Li, Zhen-Hua <zhen-hual@hp.com> wrote: >> On some IA64 platforms with intel PCI bridge, for example, HP BL890c i2 >> with Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port, >> when kernel tries to disable the mmio decoding on the PCI bridge devices, >> kernel may crash. >> >> And in the comment of function quirk_mmio_always_on, it also says: >> "But doing so (disable the mmio decoding) may cause problems on host bridge >> and perhaps other key system devices" >> >> So, for these PCI bridges, dev->mmio_always_on bit should be set to 1. >> >> >> Signed-off-by: Li, Zhen-Hua <zhen-hual@hp.com> >> --- >> drivers/pci/quirks.c | 15 +++++++++++++++ >> 1 file changed, 15 insertions(+) >> >> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c >> index e85d230..24b8024 100644 >> --- a/drivers/pci/quirks.c >> +++ b/drivers/pci/quirks.c >> @@ -44,6 +44,21 @@ static void quirk_mmio_always_on(struct pci_dev *dev) >> DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_ANY_ID, PCI_ANY_ID, >> PCI_CLASS_BRIDGE_HOST, 8, quirk_mmio_always_on); >> >> +#ifdef CONFIG_IA64 >> +/* >> + * On some IA64 platforms, for some intel PCI bridge devices, for example, >> + * the Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port, >> + * disable the mmio decoding on these devices may cause system crash. >> + * So dev->mmio_always_on bit should be set to 1. >> + */ >> +static void quirk_mmio_on_intel_pcibridge(struct pci_dev *dev) >> +{ >> + dev->mmio_always_on = 1; >> +} >> +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_ANY_ID, PCI_ANY_ID, >> + PCI_CLASS_BRIDGE_PCI, 8, quirk_mmio_on_intel_pcibridge); >> +#endif > The changelog and comment suggest an issue specific to Intel > 5520/5500/X58, but the patch sets mmio_always_on for *all* PCI > bridges. > > It claims to be specific to ia64 (and is only compiled there), but the > chipset is also used for x86. You need to explain why the problem > only affects ia64. > > Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index e85d230..24b8024 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -44,6 +44,21 @@ static void quirk_mmio_always_on(struct pci_dev *dev) DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_ANY_ID, PCI_ANY_ID, PCI_CLASS_BRIDGE_HOST, 8, quirk_mmio_always_on); +#ifdef CONFIG_IA64 +/* + * On some IA64 platforms, for some intel PCI bridge devices, for example, + * the Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port, + * disable the mmio decoding on these devices may cause system crash. + * So dev->mmio_always_on bit should be set to 1. + */ +static void quirk_mmio_on_intel_pcibridge(struct pci_dev *dev) +{ + dev->mmio_always_on = 1; +} +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_ANY_ID, PCI_ANY_ID, + PCI_CLASS_BRIDGE_PCI, 8, quirk_mmio_on_intel_pcibridge); +#endif + /* The Mellanox Tavor device gives false positive parity errors * Mark this device with a broken_parity_status, to allow * PCI scanning code to "skip" this now blacklisted device.
On some IA64 platforms with intel PCI bridge, for example, HP BL890c i2 with Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port, when kernel tries to disable the mmio decoding on the PCI bridge devices, kernel may crash. And in the comment of function quirk_mmio_always_on, it also says: "But doing so (disable the mmio decoding) may cause problems on host bridge and perhaps other key system devices" So, for these PCI bridges, dev->mmio_always_on bit should be set to 1. Signed-off-by: Li, Zhen-Hua <zhen-hual@hp.com> --- drivers/pci/quirks.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)