On 2012/10/12 8:15, Jon Mason wrote: > 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 agree, your solution is better, I will drop this patch. > 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 >> >> > > . > -- Thanks! Yijing -- 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
