Re: Kernel Display and Video API Consolidation mini-summit at ELC 2012 - Notes

On Wed, 22 Feb 2012 17:24:24 +0100, Daniel Vetter [off-list ref] wrote:

On Wed, Feb 22, 2012 at 04:03:21PM +0000, James Simmons wrote:

quoted

Fbcon scrolling at be painful at HD or better modes. Fbcon needs 3 
possible accels; copyarea, imageblit, and fillrect. The first two could be 
hooked from the TTM layer. Its something I plan to experiment to see if 
its worth it.

Let's bite into this ;-) I know that fbcon scrolling totally sucks on big
screens, but I also think it's a total waste of time to fix this. Imo
fbcon has 2 use-cases:
- display an OOSP.
- allow me to run fsck (or any other desaster-recovery stuff).

3. Show panics.

Ensuring that nothing prevents the switch to fbcon and displaying the
panic message is the reason why we haven't felt inclined to accelerate
fbcon - it just gets messy for no real gain.

For example: https://bugs.freedesktop.org/attachment.cgi?idH933
which doesn't handle flushing of pending updates via the GPU when
writing with the CPU during interrupts (i.e. a panic).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre