diff options
Diffstat (limited to 'drivers/pci/probe.c')
| -rw-r--r-- | drivers/pci/probe.c | 59 |
1 files changed, 36 insertions, 23 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 8473727b29fa..6ab6bd3df4b2 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1351,7 +1351,8 @@ static int pcie_find_smpss(struct pci_dev *dev, void *data) * will occur as normal. */ if (dev->is_hotplug_bridge && (!list_is_singular(&dev->bus->devices) || - dev->bus->self->pcie_type != PCI_EXP_TYPE_ROOT_PORT)) + (dev->bus->self && + dev->bus->self->pcie_type != PCI_EXP_TYPE_ROOT_PORT))) *smpss = 0; if (*smpss > dev->pcie_mpss) @@ -1396,34 +1397,37 @@ static void pcie_write_mps(struct pci_dev *dev, int mps) static void pcie_write_mrrs(struct pci_dev *dev, int mps) { - int rc, mrrs; + int rc, mrrs, dev_mpss; - if (pcie_bus_config == PCIE_BUS_PERFORMANCE) { - int dev_mpss = 128 << dev->pcie_mpss; + /* In the "safe" case, do not configure the MRRS. There appear to be + * issues with setting MRRS to 0 on a number of devices. + */ - /* For Max performance, the MRRS must be set to the largest - * supported value. However, it cannot be configured larger - * than the MPS the device or the bus can support. This assumes - * that the largest MRRS available on the device cannot be - * smaller than the device MPSS. - */ - mrrs = mps < dev_mpss ? mps : dev_mpss; - } else - /* In the "safe" case, configure the MRRS for fairness on the - * bus by making all devices have the same size - */ - mrrs = mps; + if (pcie_bus_config != PCIE_BUS_PERFORMANCE) + return; + dev_mpss = 128 << dev->pcie_mpss; + + /* For Max performance, the MRRS must be set to the largest supported + * value. However, it cannot be configured larger than the MPS the + * device or the bus can support. This assumes that the largest MRRS + * available on the device cannot be smaller than the device MPSS. + */ + mrrs = min(mps, dev_mpss); /* MRRS is a R/W register. Invalid values can be written, but a - * subsiquent read will verify if the value is acceptable or not. + * subsequent read will verify if the value is acceptable or not. * If the MRRS value provided is not acceptable (e.g., too large), * shrink the value until it is acceptable to the HW. */ while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) { + dev_warn(&dev->dev, "Attempting to modify the PCI-E MRRS value" + " to %d. If any issues are encountered, please try " + "running with pci=pcie_bus_safe\n", mrrs); rc = pcie_set_readrq(dev, mrrs); if (rc) - dev_err(&dev->dev, "Failed attempting to set the MRRS\n"); + dev_err(&dev->dev, + "Failed attempting to set the MRRS\n"); mrrs /= 2; } @@ -1436,13 +1440,13 @@ static int pcie_bus_configure_set(struct pci_dev *dev, void *data) if (!pci_is_pcie(dev)) return 0; - dev_info(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n", + dev_dbg(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n", pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev)); pcie_write_mps(dev, mps); pcie_write_mrrs(dev, mps); - dev_info(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n", + dev_dbg(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n", pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev)); return 0; @@ -1454,15 +1458,24 @@ static int pcie_bus_configure_set(struct pci_dev *dev, void *data) */ void pcie_bus_configure_settings(struct pci_bus *bus, u8 mpss) { - u8 smpss = mpss; + u8 smpss; - if (!bus->self) + if (!pci_is_pcie(bus->self)) return; - if (!pci_is_pcie(bus->self)) + if (pcie_bus_config == PCIE_BUS_TUNE_OFF) return; + /* FIXME - Peer to peer DMA is possible, though the endpoint would need + * to be aware to the MPS of the destination. To work around this, + * simply force the MPS of the entire system to the smallest possible. + */ + if (pcie_bus_config == PCIE_BUS_PEER2PEER) + smpss = 0; + if (pcie_bus_config == PCIE_BUS_SAFE) { + smpss = mpss; + pcie_find_smpss(bus->self, &smpss); pci_walk_bus(bus, pcie_find_smpss, &smpss); } |