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path: root/drivers/pci/pci.c
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Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c18
1 files changed, 16 insertions, 2 deletions
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;