diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 7cd417e94058..6f45a73c6e9f 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3202,8 +3202,6 @@ int pcie_set_readrq(struct pci_dev *dev, int rq) if (rq < 128 || rq > 4096 || !is_power_of_2(rq)) goto out; - v = (ffs(rq) - 8) << 12; - cap = pci_pcie_cap(dev); if (!cap) goto out; @@ -3211,6 +3209,22 @@ int pcie_set_readrq(struct pci_dev *dev, int rq) err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl); if (err) goto out; + /* + * If using the "performance" PCIe config, we clamp the + * read rq size to the max packet size to prevent the + * host bridge generating requests larger than we can + * cope with + */ + if (pcie_bus_config == PCIE_BUS_PERFORMANCE) { + int mps = pcie_get_mps(dev); + + if (mps < 0) + return mps; + if (mps < rq) + rq = mps; + } + + v = (ffs(rq) - 8) << 12; if ((ctl & PCI_EXP_DEVCTL_READRQ) != v) { ctl &= ~PCI_EXP_DEVCTL_READRQ;