| Message ID | 1585343775-4019-1-git-send-email-ashok.raj@intel.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | pci: Fixes MaxPayloadSize (MPS) programming for RCiEP devices. | expand |
Hi
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This commit has been processed because it contains a "Fixes:" tag
fixing commit: 9dae3a97297f ("PCI: Move MPS configuration check to pci_configure_device()").
The bot has tested the following trees: v5.5.13, v5.4.28, v4.19.113, v4.14.174, v4.9.217, v4.4.217.
v5.5.13: Build OK!
v5.4.28: Build OK!
v4.19.113: Build OK!
v4.14.174: Build OK!
v4.9.217: Build OK!
v4.4.217: Build failed! Errors:
drivers/pci/probe.c:1357:4: error: implicit declaration of function ‘pci_warn’; did you mean ‘pr_warn’? [-Werror=implicit-function-declaration]
NOTE: The patch will not be queued to stable trees until it is upstream.
How should we proceed with this patch?
On Fri, Mar 27, 2020 at 02:16:15PM -0700, Ashok Raj wrote: > Root Complex Integrated devices (RCiEP) do not have a Root Port before the > device. pci_configure_mps() should simply stick the max value for MaxPayload > size in Device Control, and for MaxReadReq. Unless pcie=pcie_bus-peer2peer > is used in kernel commandline PCIE_BUS_PEER2PEER. > > When MPS is configured lower, it could result in reduced performance. > > Fixes: 9dae3a97297f ("PCI: Move MPS configuration check to pci_configure_device()") > Signed-off-by: Ashok Raj <ashok.raj@intel.com> > Tested-by: Dave Jiang <dave.jiang@intel.com> > To: Bjorn Helgaas <bhelgaas@google.com> > To: linux-pci@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: stable@vger.kernel.org > Cc: Ashok Raj <ashok.raj@intel.com> Applied to pci/enumeration for v5.8, thanks! > --- > drivers/pci/probe.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index eeff8a07..a738b1c 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -1895,13 +1895,34 @@ static void pci_configure_mps(struct pci_dev *dev) > struct pci_dev *bridge = pci_upstream_bridge(dev); > int mps, mpss, p_mps, rc; > > - if (!pci_is_pcie(dev) || !bridge || !pci_is_pcie(bridge)) > + if (!pci_is_pcie(dev)) > return; > > /* MPS and MRRS fields are of type 'RsvdP' for VFs, short-circuit out */ > if (dev->is_virtfn) > return; > > + /* > + * If this is a Root Complex Integrated Endpoint > + * Simply program the max value from DEVCAP. No additional > + * Lookup is necessary > + */ > + if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) { > + if (pcie_bus_config == PCIE_BUS_PEER2PEER) > + mps = 128; > + else > + mps = 128 << dev->pcie_mpss; > + rc = pcie_set_mps(dev, mps); > + if (rc) { > + pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", > + mps); > + return; > + } > + } > + > + if (!bridge || !pci_is_pcie(bridge)) > + return; > + > mps = pcie_get_mps(dev); > p_mps = pcie_get_mps(bridge); > > -- > 2.7.4 >
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index eeff8a07..a738b1c 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1895,13 +1895,34 @@ static void pci_configure_mps(struct pci_dev *dev) struct pci_dev *bridge = pci_upstream_bridge(dev); int mps, mpss, p_mps, rc; - if (!pci_is_pcie(dev) || !bridge || !pci_is_pcie(bridge)) + if (!pci_is_pcie(dev)) return; /* MPS and MRRS fields are of type 'RsvdP' for VFs, short-circuit out */ if (dev->is_virtfn) return; + /* + * If this is a Root Complex Integrated Endpoint + * Simply program the max value from DEVCAP. No additional + * Lookup is necessary + */ + if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) { + if (pcie_bus_config == PCIE_BUS_PEER2PEER) + mps = 128; + else + mps = 128 << dev->pcie_mpss; + rc = pcie_set_mps(dev, mps); + if (rc) { + pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", + mps); + return; + } + } + + if (!bridge || !pci_is_pcie(bridge)) + return; + mps = pcie_get_mps(dev); p_mps = pcie_get_mps(bridge);
Root Complex Integrated devices (RCiEP) do not have a Root Port before the device. pci_configure_mps() should simply stick the max value for MaxPayload size in Device Control, and for MaxReadReq. Unless pcie=pcie_bus-peer2peer is used in kernel commandline PCIE_BUS_PEER2PEER. When MPS is configured lower, it could result in reduced performance. Fixes: 9dae3a97297f ("PCI: Move MPS configuration check to pci_configure_device()") Signed-off-by: Ashok Raj <ashok.raj@intel.com> Tested-by: Dave Jiang <dave.jiang@intel.com> To: Bjorn Helgaas <bhelgaas@google.com> To: linux-pci@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Cc: Ashok Raj <ashok.raj@intel.com> --- drivers/pci/probe.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-)