Re: [Linux-fbdev-devel] Re: Is a FontCache worth implementing ?

[Brad D. <br...@ne...>]

On 12 Mar 2001 04:19:06 -0800, James Simmons wrote:
> 
> >>I'm working on the removal of the console_spinlock so we can use DMA.
> >>This will greatly speed up fbcon.
> >
> >Err, ...
> >
> >so this would mean using the drm/dri stuff for doing DMA ?
> >
> >what about cards that don't have drm support yet ?
> >
> >Or will we just mess up things if we want to run simoultanous with
> >X+Accelerated OpenGL ?
> 
> No. For some cards like the intel i810 we have to use DMA/irq because we
> have no choice. Their is no mmio mode for these types of cards. Once of
> the big changes for 2.5.X is the comcept of a console state and a graphics
> state. When you open explictly /dev/fb or /dev/drm the console system
> shutdowns, via being replaced by dummy con. This prevents any conflicts
> while using the accel engine directly.

Ok, good.  This is something I was going to bring up.  Most cards will
require that they be in PIO mode before starting X.  Being in ProMo4
will surely render the machine a temporary doorstop.

It will probably have to be extended some way to change PCI access modes
when X starts regardless of /dev/drm.  How can we accomplish this
(without modifying the X driver)?

> >Will this enable us to do accelerated Mesa on fbdev ?
> 
> No. But I do have plans to merge fbdev and dri at some point in the
> future :-)

Hmm.  I'm going to take a gander at DRI API again.  I know it has
changed signifigantly since the last time I looked at it.  Maybe it
wouldn't be such a bad idea to use DRI to get in and out of ProMo4,
allocate buffers, etc.  I wonder what kinds of implications that would
have on X.

Brad Douglas
br...@ne...
http://www.linux-fbdev.org