From 468ff15a3ab98ed7153c29c68229ffb97f15a251 Mon Sep 17 00:00:00 2001 From: Yijing Wang Date: Tue, 23 Sep 2014 13:27:24 +0800 Subject: 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 Signed-off-by: Bjorn Helgaas --- Documentation/ABI/testing/sysfs-bus-pci | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'Documentation/ABI/testing/sysfs-bus-pci') 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 +Description: + 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 -- cgit v1.2.3