path: root/Documentation/ABI
diff options
authorYijing Wang <wangyijing@huawei.com>2014-09-23 13:27:24 +0800
committerBjorn Helgaas <bhelgaas@google.com>2014-10-01 12:21:23 -0600
commit468ff15a3ab98ed7153c29c68229ffb97f15a251 (patch)
tree33726cffacff157deb298a562ebac0d1062725d6 /Documentation/ABI
parent48c3c38f003c25d50a09d3da558667c5ecd530aa (diff)
PCI/MSI: Add "msi_bus" sysfs MSI/MSI-X control for endpoints
The "msi_bus" sysfs file for bridges sets a bus flag to allow or disallow future driver requests for MSI or MSI-X. Previously, the sysfs file existed for endpoints but did nothing. Add "msi_bus" support for endpoints, so an administrator can prevent the use of MSI and MSI-X for individual devices. Note that as for bridges, these changes only affect future driver requests for MSI or MSI-X, so drivers may need to be reloaded. Add documentation for the "msi_bus" sysfs file. [bhelgaas: changelog, comments, add "subordinate", add endpoint printk, rework bus_flags setting, make bus_flags printk unconditional] Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'Documentation/ABI')
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 6615fda0abfb..ee6c04036492 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -65,6 +65,16 @@ Description:
force a rescan of all PCI buses in the system, and
re-discover previously removed devices.
+What: /sys/bus/pci/devices/.../msi_bus
+Date: September 2014
+Contact: Linux PCI developers <linux-pci@vger.kernel.org>
+ Writing a zero value to this attribute disallows MSI and
+ MSI-X for any future drivers of the device. If the device
+ is a bridge, MSI and MSI-X will be disallowed for future
+ drivers of all child devices under the bridge. Drivers
+ must be reloaded for the new setting to take effect.
What: /sys/bus/pci/devices/.../msi_irqs/
Date: September, 2011
Contact: Neil Horman <nhorman@tuxdriver.com>

Privacy Policy