Messages in this thread | | | Date | Fri, 13 Aug 2004 08:53:11 -0700 (PDT) | From | Jon Smirl <> | Subject | Re: legacy VGA device requirements (was: Exposing ROM's though sysfs) |
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What should the API for this look like? We could add a VGA={0/1} attribute to all the VGA devices in sysfs.
But then how do you: 1) list all of the conflicting VGA devices in a domain? 2) turn off all the VGA devices in a domain?
We could build a bus like directory structure in /sys/class
/sys/class/vga/domain1/vga1/(device/driver/enable) /sys/class/vga/domain1/vga2/(device/driver/enable) /sys/class/vga/domain2/vga1/(device/driver/enable) /sys/class/vga/domain2/vga2/(device/driver/enable)
Then add an enable attribute in the domain directories that would shut off all of the subdevices.
/sys/class/vga/domain1/enable /sys/class/vga/domain2/enable
But the vga driver is not going to be attached to a device. Is there an easy way to build this is sysfs?
--- Jesse Barnes <jbarnes@engr.sgi.com> wrote:
> On Tuesday, August 3, 2004 5:59 pm, Benjamin Herrenschmidt wrote: > > All this could be very nicely dealt with by the kernel driver. > > So what requirements have we collected so far? > > o device selection (presumably domain, bus, slot, function) > i.e. select the device you'd like to manipulate > ioctl? > o per-domain & device VGA enable/disable > need to disable VGA ports on cards in the same domain and/or bus > ioctl? > o legacy port I/O > for properly routing I/O in multi-domain machines and machines > where the > kernel or firmware may need to trap master aborts > read/write? > o legacy memory mapping > for mapping the legacy VGA framebuffer, may fail > mmap? > > Is that a complete list? Of course, the interface mechanisms are up > for > debate too. We might be able to do it with per-bus or per-domain > files in > sysfs for the legacy I/O and memory stuff, but that might not > represent the > fact that legacy devices have interdependencies very well (e.g. VGA > ports > must be disabled on device A before we poke device B, etc.). > > Thanks, > Jesse >
===== Jon Smirl jonsmirl@yahoo.com
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