On Thu, Oct 11, 2012 at 5:03 AM, Yijing Wang <wangyijing@xxxxxxxxxx> wrote: > PCIe device mps maybe not equal to its bridge mps after doing hotplug. > This may result unexpected problem like > http://marc.info/?l=linux-scsi&m=134788365823217&w=2. So add mps log for current > mps setting to help diagnosis an issue like this. > > Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx> > --- > drivers/pci/probe.c | 29 +++++++++++++++++++++++++++++ > 1 files changed, 29 insertions(+), 0 deletions(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index ec909af..a31e615 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -1533,6 +1533,33 @@ static void pcie_write_mrrs(struct pci_dev *dev) > "with pci=pcie_bus_safe.\n"); > } > > +static int pcie_mps_info(struct pci_dev *dev, void *data) > +{ > + int mps, mpss; > + > + if (!pci_is_pcie(dev)) > + return -EINVAL; > + > + mps = pcie_get_mps(dev); > + mpss = 128 << dev->pcie_mpss; > + dev_printk(KERN_DEBUG, &dev->dev, "PCI-E Max_Payload_Size Supported %d, " > + "Max_Payload_Size %d\n", mpss, mps); > + > + return 0; > +} > + > +static void pcie_dump_mps_info(struct pci_bus *bus) > +{ > + int mps, mpss; > + > + mps = pcie_get_mps(bus->self); > + mpss = 128 << bus->self->pcie_mpss; > + dev_printk(KERN_DEBUG, &bus->self->dev, "PCI-E Max_Payload_Size Supported %d, " > + "Max_Payload_Size %d\n", mpss, mps); > + > + pci_walk_bus(bus, pcie_mps_info, NULL); > +} > + > static int pcie_bus_configure_set(struct pci_dev *dev, void *data) > { > int mps, orig_mps; > @@ -1564,6 +1591,8 @@ void pcie_bus_configure_settings(struct pci_bus *bus, u8 mpss) > if (!pci_is_pcie(bus->self)) > return; > > + pcie_dump_mps_info(bus); > + The patch looks fine, but a better way of doing things would be to create a new default pcie_bus_config state (PCIE_BUS_WARN) that: * prints the default MPS of the device * prints the suggested MPS * notifies the user that they would be better off running PCIE_BUS_SAFE (if that is the case). I have a rough version of this in my tree already. I'll try and push it out tonight. Thanks, Jon > if (pcie_bus_config == PCIE_BUS_TUNE_OFF) > return; > > -- > 1.7.1 > > -- 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
