(2011/03/25 7:21), Jordan Hargrave wrote: > Reference: http://marc.info/?l=linux-hotplug&m=128932324625063&w=2 > > The following patch sets the MaxPayload setting to match the parent reading when inserting > a PCIE card into a hotplug slot. On our system, the upstream bridge is set to 256, but when > inserting a card, the card setting defaults to 128. As soon as I/O is performed to the card > it starts receiving errors since the payload size is too small. > > Signed-off-by: Jordan_Hargrave@xxxxxxxx > > --- > drivers/pci/hotplug/pcihp_slot.c | 45 ++++++++++++++++++++++++++++++++++++++ > 1 files changed, 45 insertions(+), 0 deletions(-) > > diff --git a/drivers/pci/hotplug/pcihp_slot.c b/drivers/pci/hotplug/pcihp_slot.c > index 80b461c..912d55b 100644 > --- a/drivers/pci/hotplug/pcihp_slot.c > +++ b/drivers/pci/hotplug/pcihp_slot.c > @@ -158,6 +158,47 @@ static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp) > */ > } > > +/* Program PCIE MaxPayload setting on device: ensure parent maxpayload<= device */ > +static int pci_set_payload(struct pci_dev *dev) > +{ > + int pos, ppos; > + u16 pctl, psz; > + u16 dctl, dsz, dcap, dmax; > + struct pci_dev *parent; > + > + parent = dev->bus->self; > + pos = pci_find_capability(dev, PCI_CAP_ID_EXP); > + if (!pos) > + return 0; You can use pci_pcie_cap(), which just returns dev->pcie_cap, instead of pci_find_capability(). > + > + /* Read Device MaxPayload capability and setting */ > + pci_read_config_word(dev, pos + PCI_EXP_DEVCTL,&dctl); > + pci_read_config_word(dev, pos + PCI_EXP_DEVCAP,&dcap); > + dsz = (dctl& PCI_EXP_DEVCTL_PAYLOAD)>> 5; > + dmax = (dcap& PCI_EXP_DEVCAP_PAYLOAD); > + > + /* Read Parent MaxPayload setting */ > + ppos = pci_find_capability(parent, PCI_CAP_ID_EXP); > + if (!ppos) > + return 0; Ditto. > + pci_read_config_word(parent, ppos + PCI_EXP_DEVCTL,&pctl); > + psz = (pctl& PCI_EXP_DEVCTL_PAYLOAD)>> 5; > + > + /* If parent payload> device max payload -> error > + * If parent payload> device payload -> set speed > + * If parent payload<= device payload -> do nothing > + */ > + if (psz> dmax) > + return -1; > + else if (psz> dsz) { Maybe just "if" (not "else if") here is easier to read. > + dev_info(&dev->dev, "Setting MaxPayload to %d\n", 128<< psz); > + pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, > + (dctl& ~PCI_EXP_DEVCTL_PAYLOAD) + > + (psz<< 5)); What about dctrl = (dctrl & ~PCI_EXP_DEVCTL_PAYLOAD) | (psz << 5); pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, dctrl); ? Regards, Kenji Kaneshige -- 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
