accessibilities first tests - many questions

Jim Gettys jg at
Fri Aug 17 19:38:04 EDT 2007

On Fri, 2007-08-17 at 17:34 -0600, Jordan Crouse wrote:
> On 17/08/07 11:56 +0200, Guylhem Aznar wrote:
> > Hello,
> > 
> > The only things I don't know yet how to do with the DCON :
> >  - how to disable the smoothing algorithm applied in color mode
> We didn't enable this ability in the sysfs/ interface.  I have never
> been too clear on what the actual practical uses are for something like
> this, so the control never got added. 
> In a pinch, you can use the i2c-tools utilities to write to the device
> directly (use at your own risk!) 
> >  - how to reduce the framerate (for ex for ebook reading, but it could
> > also be handy in text mode)
> This is difficult to do - since it would involve synchronizing with the 
> video driver which with X and the framebuffer driver will invariably result
> in a screen glitch (note that just switching the rate on the DCON itself
> doesn't cause a glitch - its the software that is braindead
> here).  But we don't have any support for this in the kernel.

Actually, if the frame rate drop is just done by the dcon when it is in
control of the screen, it is glitchless; it's resetting the geode's mode
which is glitchful, and we'll avoid that.

                         - Jim

Jim Gettys
One Laptop Per Child

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