On Saturday 29 April 2006 03:04, Dave Airlie wrote:This patch adds an "enable" sysfs attribute to each PCI device. When read it
shows the "enabled-ness" of the device, but you can write a "0" into it to
disable a device, and a "1" to enable it.
This later is needed for X and other cases where userspace wants to enable
the BARs on a device (typical example: to run the video bios on a secundary
head). Right now X does all this "by hand" via bitbanging, that's just evil.
This allows X to no longer do that but to just let the kernel do this.
I'm all in favor of cleaning up X. But making the X code prettier without
changing the underlying issues of claiming and sharing resources doesn't
help much. In fact, I suspect the ultimate plan for X does not involve
an "enable" attribute in sysfs, so this may just introduce ABI cruft that
will be difficult to remove later.