I would be fine with that.. having a common one in bus.c. --jordan hargrave Dell Enterprise Linux Engineering > -----Original Message----- > From: Jon Mason [mailto:jon.mason@xxxxxxxx] > Sent: Wednesday, May 25, 2011 3:39 PM > To: Hargrave, Jordan > Cc: jbarnes@xxxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; > gallatin@xxxxxxxx > Subject: Re: [PATCH] PCI: Max Payload Size BIOS workaround > > On Wed, May 25, 2011 at 3:16 PM, <Jordan_Hargrave@xxxxxxxx> wrote: > > Hmm. I just added very similar code for setting PCIEmaxpayload during > PCIE hotplug insertion. > > perhaps these two should be merged? > > Yes, the code is nearly identical, as it is performing the same > function. > > Perhaps that code should be moved to a more common place (bus.c?), and > called at both necessary locations. Also, there probably should be a > flag to denote where it is being called, as it is a BIOS bug in my > case. > > Thanks, > Jon > > > > > --jordan hargrave > > Dell Enterprise Linux Engineering > > > >> -----Original Message----- > >> From: linux-pci-owner@xxxxxxxxxxxxxxx [mailto:linux-pci- > >> owner@xxxxxxxxxxxxxxx] On Behalf Of Jon Mason > >> Sent: Wednesday, May 25, 2011 2:01 PM > >> To: Jesse Barnes > >> Cc: linux-pci@xxxxxxxxxxxxxxx; Andrew Gallatin > >> Subject: [PATCH] PCI: Max Payload Size BIOS workaround > >> > >> Ensure that the max payload size on the root port is the same as the > >> max > >> payload size on all intermediate bridges and devices. This is > required > >> to work around buggy BIOS revisions found on various whitebox > >> motherboards which do not configure mps beyond one level below the > root > >> port. > >> > >> Signed-off-by: Jon Mason <mason@xxxxxxxx> > >> Signed-off-by: Andrew Gallatin <gallatin@xxxxxxxx> > >> --- > >> drivers/pci/bus.c | 44 > ++++++++++++++++++++++++++++++++++++++++++++ > >> 1 files changed, 44 insertions(+), 0 deletions(-) > >> > >> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > >> index 69546e9..fc16b67 100644 > >> --- a/drivers/pci/bus.c > >> +++ b/drivers/pci/bus.c > >> @@ -175,6 +175,49 @@ int pci_bus_add_child(struct pci_bus *bus) > >> return retval; > >> } > >> > >> +/* > >> + * Ensure that the max payload size on the root port is the same as > >> the max > >> + * payload size on all intermediate bridges. This is required to > work > >> around > >> + * buggy BIOS revisions found on various whitebox motherboards > which > >> do not > >> + * configure mps beyond one level below the root port. > >> + */ > >> +static void pci_mps_workaround(struct pci_dev *child, struct > pci_dev > >> *parent) > >> +{ > >> + u16 val, pmps, cmps; > >> + int cap, rc; > >> + > >> + if (!parent) > >> + return; > >> + > >> + cap = pci_find_capability(parent, PCI_CAP_ID_EXP); > >> + if (!cap) > >> + return; > >> + > >> + rc = pci_read_config_word(parent, cap + PCI_EXP_DEVCTL, &val); > >> + if (rc) > >> + return; > >> + > >> + pmps = val & PCI_EXP_DEVCTL_PAYLOAD; > >> + > >> + cap = pci_find_capability(child, PCI_CAP_ID_EXP); > >> + if (!cap) > >> + return; > >> + > >> + rc = pci_read_config_word(child, cap + PCI_EXP_DEVCTL, &val); > >> + if (rc) > >> + return; > >> + > >> + cmps = val & PCI_EXP_DEVCTL_PAYLOAD; > >> + > >> + if (pmps != cmps) { > >> + printk(KERN_WARNING "Child MPS of %d != Parent MPS of > %d! > >> " > >> + "Most likely caused by bad BIOS. Working > >> around...\n", > >> + 128 << (cmps >> 5), 128 << (pmps >> 5)); > >> + val = (val & ~ PCI_EXP_DEVCTL_PAYLOAD) | pmps; > >> + pci_write_config_word(child, cap + PCI_EXP_DEVCTL, > val); > >> + } > >> +} > >> + > >> /** > >> * pci_bus_add_devices - insert newly discovered PCI devices > >> * @bus: bus to check for new devices > >> @@ -194,6 +237,7 @@ void pci_bus_add_devices(const struct pci_bus > *bus) > >> int retval; > >> > >> list_for_each_entry(dev, &bus->devices, bus_list) { > >> + pci_mps_workaround(dev, dev->bus->self); > >> /* Skip already-added devices */ > >> if (dev->is_added) > >> continue; > >> -- > >> 1.7.4.1 > >> > >> -- > >> 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 > > -- 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
