[maemo-developers] Does anyone know the mechanism in Nokia's LCD driver?

[From: Siarhei Siamashka]

On Tue, Jan 13, 2009 at 10:56 AM, Frantisek Dufka <dufkaf at seznam.cz> wrote:
> BTW, there is kernel ioctl to set automatic refresh and the refresh rate
> can be tweaked in kernel source but the results are suboptimal. Maybe at
> least for Nokia 770 it would be possible to use tearsync flag for such
> automatic update and set the update timer to lcd refresh rate or lcd
> refresh rate/2 to get nice result. N8x0 cannot update whole screen in
> one lcd refresh cycle anyway so you'll always get tearing on the bottom.

N8x0 can update whole screen in two lcd refresh cycles (but admittedly
it just barely crosses this limit), which is enough to have no
tearing. But this is only true when running at OP 0 (400MHz). When
running at other operating points, RFBI is slower. It may be
interesting to experiment with better integration of omapfb kernel
driver with DVFS and try to always switch (at least temporarily) to OP
0 when performing screen updates.