Re: Add a "enable" sysfs attribute to the pci devices to allow userspace (Xorg) to enable devices without doing foul direct access

[Greg KH <greg@kroah.com>]

On Fri, May 05, 2006 at 04:35:17PM -0400, Jon Smirl wrote:
> On 5/5/06, Greg KH <greg@kroah.com> wrote:
> >On Fri, May 05, 2006 at 04:14:00PM -0400, Jon Smirl wrote:
> >> I would like to see other design alternatives considered on this
> >> issue. The 'enable' attribute has a clear problem in that you can't
> >> tell which user space program is trying to control the device.
> >> Multiple programs accessing the video hardware with poor coordination
> >> is already the source of many problems.
> >
> >Who cares who "enabled" the device.  Remember, the majority of PCI
> >devices in the system are not video ones.  Lots of other types of
> >devices want this ability to enable PCI devices from userspace.  I've
> >been talking with some people about how to properly write PCI drivers in
> >userspace, and this attribute is a needed part of it.
> 
> User space program enables the device.
> Next I load a device driver
> next I rmmod the device driver and it disables the device
> user space program trys to use the device
> No coordination and user space program faults

Gun.  Foot.  Shoot.

> Don't say this can't happen, it is a current source of conflict
> between X and fbdev.

Not a PCI kernel issue :)

> Should we just remove the ability to disable hardware?

Huh?  Why?

> How would that interact with hotplug?

What does hotplug have to do at all with this?

thanks,

greg "not all the world is video cards" k-h
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/