path: root/Documentation/kernel-parameters.txt
diff options
authorKeith Busch <keith.busch@intel.com>2016-07-21 21:40:28 -0600
committerBjorn Helgaas <bhelgaas@google.com>2016-07-25 12:52:47 -0500
commite16b46605960bd071a3e26f316e0bb600ae91e37 (patch)
treecbddd9ca52a24d2a414c48e375d89f8c36596087 /Documentation/kernel-parameters.txt
parentaf8c34ce6ae32addda3788d54a7e340cad22516b (diff)
PCI: Allow additional bus numbers for hotplug bridges
A user may hot add a switch requiring more than one bus to enumerate. This previously required a system reboot if BIOS did not sufficiently pad the bus resource, which they frequently don't do. Add a kernel parameter so a user can specify the minimum number of bus numbers to reserve for a hotplug bridge's subordinate buses so rebooting won't be necessary. The default is 1, which is equivalent to previous behavior. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 82b42c958d1c..487e799b1da2 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3016,6 +3016,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
hpmemsize=nn[KMG] The fixed amount of bus space which is
reserved for hotplug bridge's memory window.
Default size is 2 megabytes.
+ hpbussize=nn The minimum amount of additional bus numbers
+ reserved for buses below a hotplug bridge.
+ Default is 1.
realloc= Enable/disable reallocating PCI bridge resources
if allocations done by BIOS are too small to
accommodate resources required by all child