Re: [Linux-fbdev-users] CT65550 / chipsfb driver status...

[Laurence A. <la...@cl...>]

On Mon, 2004-10-25 at 13:34, Antonino A. Daplas wrote:
> On Monday 25 October 2004 16:34, Laurence Abbott wrote:
> > I'm not totally sure how I work with multiple framebuffer devices: my
> > AGP card gives me two: /dev/fb/0 which works as I'd expect, and
> > /dev/fb/2, which I think may be TV-out, or something, but this one is
> > only VGA16. The ct65550 one appears as /dev/fb/1
> 
> Doing a cat /proc/fb should tell you what drivers are loaded. What kernel
> version are you using?

This is a 2.6.8 kernel. Yes, /proc/fb does give the numbers I said
above. I also have a /proc/fb0 directory with a couple of files in it
(cannot check at the moment) but no /proc/fb1 or /proc/fb2 (could be
related to vesafb-tng?).

> > I'm currently using the vesafb-tng driver (as part of Gentoo) and think
> > that this may be causing some of my problems! If I use:
> >
> > % fbset -fb /dev/fb/1
> >
> > It tells me that the ct65550 is running in 800 x 600 and 8-bit depth.
> > Fair enough. If I try to change the depth on that framebuffer, it
> > corrupts /dev/fb/0 and I can no longer see what I'm doing! I will try
> 
> Normal behavior is not to affect /dev/fb0 if the command is explicit
> to /dev/fb1.  So there is a bug somewhere.  (however, this may happen
> if you have 2 drivers for the same physical device, say vga16fb and
> a driver specific driver)

I will try without compiling support for VGA16 so the second FB on my
AGP card is ignored (hopefully!).

> > with the standard vesafb driver tonight to see if that works any better.
> >
> > In the framebuffer HOWTO, it says that you can only run fbset from teh
> > framebuffer itself. Is this the case? Surely that is the whole point of
> > the -fb switch!
> 
> No, you can run fbset anywhere, even within xterm, if you have the guts.
> If there is no -fb, it defaults to /dev/fb0.

This is what I was hoping...

> > Is there a simple command which can be used to restore a framebuffer
> > back to a sane state, rather than having to reboot?
> 
> There are a few drivers that can restore the hardware state, but the answer
> is generally no.  You can try to have > 1 video cards, load each of their
> drivers.  If your console becomes corrupt, you can use con2fbmap to
> move your console to the known working driver.

I have some more testing to do now...

Thanks,

Laz