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authorEmil Velikov <emil.velikov@collabora.com>2016-11-22 01:24:49 +0300
committerBjorn Helgaas <bhelgaas@google.com>2016-11-22 01:25:32 +0300
commit702ed3be1b1bf4dea05954168321741c0910c645 (patch)
tree4148dde5865bb993433dbf80be09d7a26b2121ca /drivers/pci
parent1001354ca34179f3db924eb66672442a173147dc (diff)
downloadlinux-702ed3be1b1bf4dea05954168321741c0910c645.tar.xz
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 <registo.mailling@gmail.com> Signed-off-by: Emil Velikov <emil.velikov@collabora.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch CC: Greg KH <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/pci-sysfs.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index bcd10c795284..066628776e1b 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -50,6 +50,7 @@ pci_config_attr(vendor, "0x%04x\n");
pci_config_attr(device, "0x%04x\n");
pci_config_attr(subsystem_vendor, "0x%04x\n");
pci_config_attr(subsystem_device, "0x%04x\n");
+pci_config_attr(revision, "0x%02x\n");
pci_config_attr(class, "0x%06x\n");
pci_config_attr(irq, "%u\n");
@@ -568,6 +569,7 @@ static struct attribute *pci_dev_attrs[] = {
&dev_attr_device.attr,
&dev_attr_subsystem_vendor.attr,
&dev_attr_subsystem_device.attr,
+ &dev_attr_revision.attr,
&dev_attr_class.attr,
&dev_attr_irq.attr,
&dev_attr_local_cpus.attr,