| Message ID | 20170712193432.GD14614@bhelgaas-glaptop.roam.corp.google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Thu, Jul 13, 2017 at 3:34 AM, Bjorn Helgaas <helgaas@kernel.org> wrote: > On Wed, Jul 12, 2017 at 08:15:43AM -0400, Sinan Kaya wrote: >> On 7/12/2017 5:44 AM, Ethan Zhao wrote: >> > The dmesg yelled "...Tag handling is broken" , but didn't say how it >> > was handled, that is weird and confusing, just because there is no >> > device under that bridge ? >> > >> > How about move the messages together "...is broken, disable Extended tag..." > > I changed the message this: > > pci 0000:00:07.0: disabling Extended Tags (this device can't handle them) > > We don't see any message from 0000:01:00.0 itself because it powered up > with Extended Tags disabled. If it powered up with Extended Tags *enabled* > (as allowed by the ECN), we would see this: > > pci 0000:00:07.0: disabling Extended Tags (this device can't handle them) > pci 0000:01:00.0: disabling Extended Tags > > Does that seem reasonable? Complete updated patch attached below. > >> This was something requested by Bjorn to inform that user has a broken HW >> when a quirk is matched. >> >> The new code will disable extended tags only if it was enabled on endpoint >> via power on reset value or via some broken BIOS. >> >> It looks like we are not seeing any disabling message. This implies that >> both the card and BIOS is good. >> >> That's why, you are no longer seeing a disabling message on this system >> and code is just not enabling extended tags. > > > commit 2e6e588b99c4c7fbcea55eb48890fa8d0ab0c3d7 > Author: Sinan Kaya <okaya@codeaurora.org> > Date: Wed Jul 12 00:04:14 2017 -0400 > > PCI: Mark Broadcom HT2100 Root Port Extended Tags as broken > > Per PCIe r3.1, sec 2.2.6.2 and 7.8.4, a Requester may not use 8-bit Tags > unless its Extended Tag Field Enable is set, but all Receivers/Completers > must handle 8-bit Tags correctly regardless of their Extended Tag Field > Enable. > > Some devices do not handle 8-bit Tags as Completers, so add a quirk for > them. If we find such a device, we disable Extended Tags for the entire > hierarchy to make peer-to-peer DMA possible. > > The Broadcom HT2100 seems to have issues with handling 8-bit tags. Mark it > as broken. > > The pci_walk_bus() in the quirk handles devices we've enumerated in the > past, and pci_configure_device() handles devices we enumerate in the > future. > > Fixes: 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported") > Link: https://bugzilla.redhat.com/show_bug.cgi?id=1467674 > Reported-and-tested-by: Wim ten Have <wim.ten.have@oracle.com> > Signed-off-by: Sinan Kaya <okaya@codeaurora.org> > [bhelgaas: changelog, tweak messages, rename bit and quirk] > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 03e3d0285aea..9c3d123d358f 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -234,6 +234,7 @@ enum pci_bar_type { > pci_bar_mem64, /* A 64-bit memory BAR */ > }; > > +int pci_configure_extended_tags(struct pci_dev *dev, void *ign); > bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, > int crs_timeout); > int pci_setup_device(struct pci_dev *dev); > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index c31310db0404..c81c9835f4c7 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -1745,21 +1745,50 @@ static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp) > */ > } > > -static void pci_configure_extended_tags(struct pci_dev *dev) > +int pci_configure_extended_tags(struct pci_dev *dev, void *ign) > { > - u32 dev_cap; > + struct pci_host_bridge *host; > + u32 cap; > + u16 ctl; > int ret; > > if (!pci_is_pcie(dev)) > - return; > + return 0; > > - ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &dev_cap); > + ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); > if (ret) > - return; > + return 0; > + > + if (!(cap & PCI_EXP_DEVCAP_EXT_TAG)) > + return 0; > > - if (dev_cap & PCI_EXP_DEVCAP_EXT_TAG) > + ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); > + if (ret) > + return 0; > + > + host = pci_find_host_bridge(dev->bus); > + if (!host) > + return 0; > + > + /* > + * If some device in the hierarchy doesn't handle Extended Tags > + * correctly, make sure they're disabled. > + */ > + if (host->no_ext_tags) { > + if (ctl & PCI_EXP_DEVCTL_EXT_TAG) { > + dev_info(&dev->dev, "disabling Extended Tags\n"); > + pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, > + PCI_EXP_DEVCTL_EXT_TAG); > + } > + return 0; > + } > + > + if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) { > + dev_info(&dev->dev, "enabling Extended Tags\n"); > pcie_capability_set_word(dev, PCI_EXP_DEVCTL, > PCI_EXP_DEVCTL_EXT_TAG); > + } > + return 0; > } > > static void pci_configure_device(struct pci_dev *dev) > @@ -1768,7 +1797,7 @@ static void pci_configure_device(struct pci_dev *dev) > int ret; > > pci_configure_mps(dev); > - pci_configure_extended_tags(dev); > + pci_configure_extended_tags(dev, NULL); > > memset(&hpp, 0, sizeof(hpp)); > ret = pci_get_hp_params(dev, &hpp); > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index 6967c6b4cf6b..f135765555c9 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -4681,3 +4681,19 @@ static void quirk_intel_no_flr(struct pci_dev *dev) > } > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_intel_no_flr); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_intel_no_flr); > + > +static void quirk_no_ext_tags(struct pci_dev *pdev) > +{ > + struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus); > + > + if (!bridge) > + return; > + > + bridge->no_ext_tags = 1; > + dev_info(&pdev->dev, "disabling Extended Tags (this device can't handle them)\n"); A late 'Great !', at least we get reason - (this device can't handle them) and result - (disabling Extended Tags) at the same time, feel better. Thanks, Ethan > + > + pci_walk_bus(bridge->bus, pci_configure_extended_tags, NULL); > +} > +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0140, quirk_no_ext_tags); > +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0142, quirk_no_ext_tags); > +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0144, quirk_no_ext_tags); > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 4869e66dd659..3b968d435895 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -451,6 +451,7 @@ struct pci_host_bridge { > void *release_data; > struct msi_controller *msi; > unsigned int ignore_reset_delay:1; /* for entire hierarchy */ > + unsigned int no_ext_tags:1; /* no Extended Tags */ > /* Resource alignment requirements */ > resource_size_t (*align_resource)(struct pci_dev *dev, > const struct resource *res,
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 03e3d0285aea..9c3d123d358f 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -234,6 +234,7 @@ enum pci_bar_type { pci_bar_mem64, /* A 64-bit memory BAR */ }; +int pci_configure_extended_tags(struct pci_dev *dev, void *ign); bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *pl, int crs_timeout); int pci_setup_device(struct pci_dev *dev); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c31310db0404..c81c9835f4c7 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1745,21 +1745,50 @@ static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp) */ } -static void pci_configure_extended_tags(struct pci_dev *dev) +int pci_configure_extended_tags(struct pci_dev *dev, void *ign) { - u32 dev_cap; + struct pci_host_bridge *host; + u32 cap; + u16 ctl; int ret; if (!pci_is_pcie(dev)) - return; + return 0; - ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &dev_cap); + ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); if (ret) - return; + return 0; + + if (!(cap & PCI_EXP_DEVCAP_EXT_TAG)) + return 0; - if (dev_cap & PCI_EXP_DEVCAP_EXT_TAG) + ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); + if (ret) + return 0; + + host = pci_find_host_bridge(dev->bus); + if (!host) + return 0; + + /* + * If some device in the hierarchy doesn't handle Extended Tags + * correctly, make sure they're disabled. + */ + if (host->no_ext_tags) { + if (ctl & PCI_EXP_DEVCTL_EXT_TAG) { + dev_info(&dev->dev, "disabling Extended Tags\n"); + pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, + PCI_EXP_DEVCTL_EXT_TAG); + } + return 0; + } + + if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) { + dev_info(&dev->dev, "enabling Extended Tags\n"); pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_EXT_TAG); + } + return 0; } static void pci_configure_device(struct pci_dev *dev) @@ -1768,7 +1797,7 @@ static void pci_configure_device(struct pci_dev *dev) int ret; pci_configure_mps(dev); - pci_configure_extended_tags(dev); + pci_configure_extended_tags(dev, NULL); memset(&hpp, 0, sizeof(hpp)); ret = pci_get_hp_params(dev, &hpp); diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 6967c6b4cf6b..f135765555c9 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -4681,3 +4681,19 @@ static void quirk_intel_no_flr(struct pci_dev *dev) } DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_intel_no_flr); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_intel_no_flr); + +static void quirk_no_ext_tags(struct pci_dev *pdev) +{ + struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus); + + if (!bridge) + return; + + bridge->no_ext_tags = 1; + dev_info(&pdev->dev, "disabling Extended Tags (this device can't handle them)\n"); + + pci_walk_bus(bridge->bus, pci_configure_extended_tags, NULL); +} +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0140, quirk_no_ext_tags); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0142, quirk_no_ext_tags); +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, 0x0144, quirk_no_ext_tags); diff --git a/include/linux/pci.h b/include/linux/pci.h index 4869e66dd659..3b968d435895 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -451,6 +451,7 @@ struct pci_host_bridge { void *release_data; struct msi_controller *msi; unsigned int ignore_reset_delay:1; /* for entire hierarchy */ + unsigned int no_ext_tags:1; /* no Extended Tags */ /* Resource alignment requirements */ resource_size_t (*align_resource)(struct pci_dev *dev, const struct resource *res,