Re: [PATCH] fbdev: workaround for broken X servers

["Ville Syrjälä" <syrjala@sci.fi>]

On Wed, Nov 03, 2004 at 09:09:29PM +0800, Antonino A. Daplas wrote:
> On Wednesday 03 November 2004 11:26, Ville Syrjälä wrote:
> > On Wed, Nov 03, 2004 at 01:13:39PM +1100, Benjamin Herrenschmidt wrote:
> > > Hi !
> > >
> > > +	/* Workaround for broken X servers */
> > > +	if (blank > VESA_POWERDOWN)
> > > +		blank = VESA_POWERDOWN;
> > > +
> > >  	if (info->fbops->fb_blank && !info->fbops->fb_blank(blank, info))
> > >  		return 0;
> >
> > This goes against documented behaviour (see fb.h). Also drivers/char/vt.c
> > seems to agree with fb.h, as do at least atyfb and matroxfb. I also used
> > the vesa level+1 convention in DirectFB. So AFAICS this patch would
> > confuse console power management, XFree86/X.Org, DirectFB and some fb
> > drivers.
> 
> True enough. The convention is if the display is active, then suspend. If
> it is suspended, then powerdown.  And if already powered down, then do
> nothing.  It does so by by sending a blank flag of VESA_POWERDOWN + 1.
> 
> This is the convention used by the vt layer, I don't what is used by 
> user apps.

XFree86/X.Org and DirectFB both use vesa level+1. I'm not sure if there 
are other userspace users.

> The above patch won't break console power management as the console calls
> fbcon_blank(), not fb_blank().

But fbcon_blank() calls fb_blank() does it not?

-- 
Ville Syrjälä
syrjala@sci.fi
http://www.sci.fi/~syrjala/


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