[Intel-gfx] [RFC] drm: implement DRM_IOCTL_MODE_SETROTATION

[Jesse Barnes]

On Thu, 05 Jan 2012 19:10:43 -0800
Eric Anholt <eric at anholt.net> wrote:

> On Thu,  5 Jan 2012 14:16:23 -0200, przanoni at gmail.com wrote:
> > From: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > 
> > This ioctl is used to signal the drivers that the screen is rotated,
> > not to make the drivers rotate the screen.
> >  - add a driver-specific "rotation_set" function
> >  - implement Intel's rotation_set by setting the right values to the
> >    PIPECONF registers.
> > 
> > The idea is that when user-space does rotation, it can call this ioctl
> > to inform the Kernel that we have a rotation. This feature is needed
> > by the KVMr feature of VPro.
> 
> So am I following this right, that these register bits are used to
> communicate from one piece of software to another piece of software,
> across the virtualization boundary?

Right, but not for virtualization; these bits are read by the AMT
engine for its built-in KVM functionality.

-- 
Jesse Barnes, Intel Open Source Technology Center