diff options
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/probe.c | 55 |
1 files changed, 24 insertions, 31 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 6ab6bd3df4b..48294243985 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1363,31 +1363,25 @@ static int pcie_find_smpss(struct pci_dev *dev, void *data) static void pcie_write_mps(struct pci_dev *dev, int mps) { - int rc, dev_mpss; - - dev_mpss = 128 << dev->pcie_mpss; + int rc; if (pcie_bus_config == PCIE_BUS_PERFORMANCE) { - if (dev->bus->self) { - dev_dbg(&dev->bus->dev, "Bus MPSS %d\n", - 128 << dev->bus->self->pcie_mpss); + mps = 128 << dev->pcie_mpss; - /* For "MPS Force Max", the assumption is made that + if (dev->pcie_type != PCI_EXP_TYPE_ROOT_PORT && dev->bus->self) + /* For "Performance", the assumption is made that * downstream communication will never be larger than * the MRRS. So, the MPS only needs to be configured * for the upstream communication. This being the case, * walk from the top down and set the MPS of the child * to that of the parent bus. + * + * Configure the device MPS with the smaller of the + * device MPSS or the bridge MPS (which is assumed to be + * properly configured at this point to the largest + * allowable MPS based on its parent bus). */ - mps = 128 << dev->bus->self->pcie_mpss; - if (mps > dev_mpss) - dev_warn(&dev->dev, "MPS configured higher than" - " maximum supported by the device. If" - " a bus issue occurs, try running with" - " pci=pcie_bus_safe.\n"); - } - - dev->pcie_mpss = ffs(mps) - 8; + mps = min(mps, pcie_get_mps(dev->bus->self)); } rc = pcie_set_mps(dev, mps); @@ -1395,25 +1389,22 @@ static void pcie_write_mps(struct pci_dev *dev, int mps) dev_err(&dev->dev, "Failed attempting to set the MPS\n"); } -static void pcie_write_mrrs(struct pci_dev *dev, int mps) +static void pcie_write_mrrs(struct pci_dev *dev) { - int rc, mrrs, dev_mpss; + int rc, mrrs; /* In the "safe" case, do not configure the MRRS. There appear to be * issues with setting MRRS to 0 on a number of devices. */ - 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. + * device or the bus can support. This should already be properly + * configured by a prior call to pcie_write_mps. */ - mrrs = min(mps, dev_mpss); + mrrs = pcie_get_mps(dev); /* MRRS is a R/W register. Invalid values can be written, but a * subsequent read will verify if the value is acceptable or not. @@ -1421,16 +1412,18 @@ static void pcie_write_mrrs(struct pci_dev *dev, int mps) * 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"); + if (!rc) + break; + dev_warn(&dev->dev, "Failed attempting to set the MRRS\n"); mrrs /= 2; } + + if (mrrs < 128) + dev_err(&dev->dev, "MRRS was unable to be configured with a " + "safe value. If problems are experienced, try running " + "with pci=pcie_bus_safe.\n"); } static int pcie_bus_configure_set(struct pci_dev *dev, void *data) @@ -1444,7 +1437,7 @@ static int pcie_bus_configure_set(struct pci_dev *dev, void *data) pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev)); pcie_write_mps(dev, mps); - pcie_write_mrrs(dev, mps); + pcie_write_mrrs(dev); dev_dbg(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n", pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev)); |