> -----Original Message----- > From: Kenji Kaneshige [mailto:kaneshige.kenji@xxxxxxxxxxxxxx] > Sent: Thursday, March 24, 2011 8:07 PM > To: Hargrave, Jordan > Cc: linux-hotplug@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; > jbarnes@xxxxxxxxxxxxxxxx > Subject: Re: [PATCH] Set PCIE maxpayload for card during hotplug > insertion > > (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 Signed-off-by: Jordan Hargrave <Jordan_Hargrave@xxxxxxxx> --- drivers/pci/hotplug/pcihp_slot.c | 44 ++++++++++++++++++++++++++++++++++++++ 1 files changed, 44 insertions(+), 0 deletions(-) diff --git a/drivers/pci/hotplug/pcihp_slot.c b/drivers/pci/hotplug/pcihp_slot.c index 80b461c..3b628c5 100644 --- a/drivers/pci/hotplug/pcihp_slot.c +++ b/drivers/pci/hotplug/pcihp_slot.c @@ -158,6 +158,46 @@ 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_pcie_cap(dev); + if (!pos) + return 0; + + /* 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_pcie_cap(parent); + if (!ppos) + return 0; + 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; + if (psz > dsz) { + dev_info(&dev->dev, "Setting MaxPayload to %d\n", 128 << psz); + dctl = (dctl & ~PCI_EXP_DEVCTL_PAYLOAD) + (psz << 5); + pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, dctl); + } + return 0; +} + void pci_configure_slot(struct pci_dev *dev) { struct pci_dev *cdev; @@ -169,6 +209,10 @@ void pci_configure_slot(struct pci_dev *dev) (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI))) return; + ret = pci_set_payload(dev); + if (ret) + dev_warn(&dev->dev, "could not set device max payload\n"); + memset(&hpp, 0, sizeof(hpp)); ret = pci_get_hp_params(dev, &hpp); if (ret) -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
