v0->v1: Update MPS parameters as non-arch and add MRRS description into pcie_bus_perf parameter suggested by Andrew Murray. v1->v2: Update some semantic problems and add MPS and MRRS explanation suggested by Joe Lawrence and Randy Dunlap. v2->v3: Update some semantic problems and the description of pcie_bus_safe and pcie_bus_peer2peer suggested by Bjorn Helgaas. Document PCIE BUS MPS parameters pcie_bus_tune_off, pcie_bus_safe, pcie_bus_peer2peer, pcie_bus_perf into Documentation/kernel-parameters.txt. These parameters were introduced by Jon Mason <mason@xxxxxxxx> at commit 5f39e6705 and commit b03e7495a8. Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx> --- Documentation/kernel-parameters.txt | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 363e348..2997df2 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2227,6 +2227,19 @@ bytes respectively. Such letter suffixes can also be entirely omitted. This sorting is done to get a device order compatible with older (<= 2.4) kernels. nobfsort Don't sort PCI devices into breadth-first order. + pcie_bus_tune_off Disable PCIe MPS (Max Payload Size) + tuning and use the BIOS-configured MPS defaults. + pcie_bus_safe Use the smallest supported MPS of any device + below a root complex. + pcie_bus_perf Configure device MPS to the largest + allowable MPS based on its parent bus. Also set + MRRS (Max Read Request Size) to the largest supported + value (no larger than the MPS that the device or bus + can support) for best performance. + pcie_bus_peer2peer Set every device's MPS to 128B, which + every device is guaranteed to support. This + configuration allows peer-to-peer DMA between any pair + of devices possibly at the cost of reduced performance. cbiosize=nn[KMG] The fixed amount of bus space which is reserved for the CardBus bridge's IO window. The default value is 256 bytes. -- 1.7.1 -- 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
