From 702ed3be1b1bf4dea05954168321741c0910c645 Mon Sep 17 00:00:00 2001 From: Emil Velikov Date: Mon, 21 Nov 2016 16:24:49 -0600 Subject: PCI: Create revision file in sysfs Currently the revision isn't available via sysfs/libudev thus if one wants to know the value one needs to read through the config file, which can be quite time-consuming because it wakes/powers up the device. There are at least two userspace components which could make use the new file: libpciaccess and libdrm. The former wakes up _every_ PCI device, which can be observed via glxinfo when using Mesa 10.0+ drivers. The latter, in association with Mesa 13.0, can lead to 2-3 second delays while starting firefox, thunderbird or chromium. Link: https://bugs.freedesktop.org/show_bug.cgi?id=98502 Tested-by: Mauro Santos Signed-off-by: Emil Velikov Signed-off-by: Bjorn Helgaas Reviewed-by: Alex Deucher Reviewed-by: Daniel Vetter --- Documentation/ABI/testing/sysfs-bus-pci | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index b3bc50f650ee..5a1732b78707 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -294,3 +294,10 @@ Description: a firmware bug to the system vendor. Writing to this file taints the kernel with TAINT_FIRMWARE_WORKAROUND, which reduces the supportability of your system. + +What: /sys/bus/pci/devices/.../revision +Date: November 2016 +Contact: Emil Velikov +Description: + This file contains the revision field of the the PCI device. + The value comes from device config space. The file is read only. -- cgit