From 43c16408842b0eeb367c23a6fa540ce69f99e347 Mon Sep 17 00:00:00 2001 From: Andrew Patterson Date: Wed, 22 Apr 2009 16:52:09 -0600 Subject: PCI: Add support for turning PCIe ECRC on or off Adds support for PCI Express transaction layer end-to-end CRC checking (ECRC). This patch will enable/disable ECRC checking by setting/clearing the ECRC Check Enable and/or ECRC Generation Enable bits for devices that support ECRC. The ECRC setting is controlled by the "pci=ecrc=" command-line option. If this option is not set or is set to 'bios", the enable and generation bits are left in whatever state that firmware/BIOS set them to. The "off" setting turns them off, and the "on" option turns them on (if the device supports it). Turning ECRC on or off can be a data integrity versus performance tradeoff. In theory, turning it on will catch more data errors, turning it off means possibly better performance since CRC does not need to be calculated by the PCIe hardware and packet sizes are reduced. Signed-off-by: Andrew Patterson Signed-off-by: Jesse Barnes --- Documentation/kernel-parameters.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 7bdaf5080408..395d1a013ebb 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1824,6 +1824,12 @@ and is between 256 and 4096 characters. It is defined in the file PAGE_SIZE is used as alignment. PCI-PCI bridge can be specified, if resource windows need to be expanded. + ecrc= Enable/disable PCIe ECRC (transaction layer + end-to-end CRC checking). + bios: Use BIOS/firmware settings. This is the + the default. + off: Turn ECRC off + on: Turn ECRC on. pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power Management. -- cgit v1.2.1