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| author | Mathias Koehrer <mathias.koehrer@etas.com> | 2016-08-09 11:33:31 +0300 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2016-08-09 19:59:15 +0300 |
| commit | 8b078c603249239f597dc395ac182667c8e0af9c (patch) | |
| tree | 2e739d947afb3ec057c06083821aaf55510d72a1 /Documentation | |
| parent | 29b4817d4018df78086157ea3a55c1d9424a7cfc (diff) | |
| download | linux-8b078c603249239f597dc395ac182667c8e0af9c.tar.xz | |
PCI: Update "pci=resource_alignment" documentation
Some uio based PCI drivers, e.g., uio_cif, do not work if the assigned PCI
memory resources are not page aligned. By using the kernel option
"pci=resource_alignment=<align>@<bus>:<slot>.<func>" it is possible to
request page alignment for memory resources of devices.
However, this is cumbersome when using several devices, and the
bus/slot/func addresses may change if devices are added to or removed from
the system.
Extend the "pci=resource_alignment" option so we can specify the relevant
devices via PCI vendor, device, subvendor, and subdevice IDs. The
specification of the devices via IDs is indicated by a leading string
"pci:" as argument to "pci=resource_alignment".
The format of the specification is
pci:<vendor>:<device>[:<subvendor>:<subdevice>]
Examples:
pci=resource_alignment=4096@pci:8086:9c22:103c:198f
pci=resource_alignment=pci:8086:9c22 # defaults to PAGE_SIZE align
[bhelgaas: changelog, use actual vendor/device IDs in examples]
Signed-off-by: Mathias Koehrer <mathias.koehrer@etas.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 46c030a49186..a4f4d693e2c1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3032,6 +3032,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. PAGE_SIZE is used as alignment. PCI-PCI bridge can be specified, if resource windows need to be expanded. + To specify the alignment for several + instances of a device, the PCI vendor, + device, subvendor, and subdevice may be + specified, e.g., 4096@pci:8086:9c22:103c:198f ecrc= Enable/disable PCIe ECRC (transaction layer end-to-end CRC checking). bios: Use BIOS/firmware settings. This is the |