Re: N8x0 display support (was: Re: The old omapfb support)

[Tomi Valkeinen <tomi.valkeinen@ti.com>]

On Fri, 2011-04-29 at 23:04 +0200, Michael Büsch wrote:
> On Fri, 2011-04-29 at 16:33 +0300, Tomi Valkeinen wrote: 
> > So, my question is: what are the uses of N800's display with the
> > mainline kernel? Are we happy with just having basic display
> > functionality, or do people need all the features in the older blizzard
> > driver?
> 
> Well, not sure.
> The OpenWRT project runs an X server on the n810.
> It does so by using the X.org "omapfb" driver module, which
> accesses the hardware through /dev/fb0.
> http://git.pingu.fi/xf86-video-omapfb/

A quick grep shows that there's some manual update support in that tree.
However, all the OMAPFB_UPDATE_WINDOW calls are in omapfb-xv-blizzard.c,
and to me it looks like manual-update is used when Xv is being used, and
auto-update otherwise. So that probably needs some work, either in the
driver or in X.

Perhaps I'll see if I can add deferred IO support to omapfb driver,
which would be turned on when a manual-update display is set to
auto-update mode. That's not exactly the same as auto update, but I
guess it should work for almost all the cases.

While I don't like having auto-update for manual-update displays, I
guess it's still good to have for testing and prototyping purposes.

> So we basically need that to work in one way or another.
> Another thing that we require is turning off the display for
> power saving reasons. We currently do this through
> FBIOBLANK ioctl with parameters FB_BLANK_POWERDOWN/FB_BLANK_UNBLANK.
> (The backlight is turned off by other means with the device asic)

Blanking works with FBIOBLANK. It also turns off the backlight. The
backlight brightness can be controlled
via /sys/class/backlight/display0/

 Tomi


--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html