Re: CVS commit: src/sys/dev/sbus

[Andrew Doran <ad%NetBSD.org@localhost>]

On Fri, Mar 27, 2009 at 04:31:33PM -0400, Michael wrote:

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> 
> Hello,
> 
> On Mar 27, 2009, at 9:07 AM, Izumi Tsutsui wrote:
> 
> >ad%NetBSD.org@localhost wrote:
> >
> >>On Fri, Mar 27, 2009 at 12:25:41PM +0000, Izumi Tsutsui wrote:
> >>
> >>>Log Message:
> >>>Use bus_space(9) to access registers.  SETREG() macro using bogus  
> >>>casts
> >>>against packed structures doesn't work on gcc4. (no character on  
> >>>screen)
> >>>See also:
> >>>http://mail-index.NetBSD.org/port-sparc/2003/11/11/0002.html
> >>
> >>It has been a long time, but from what I remember SETREG() was an  
> >>invention
> >>of mine to work around either a compiler or code bug. Maybe  
> >>bus_space does
> >>the same.
> >
> >I'm not sure if it's a compiler bug or not, but SETREG() doesn't work
> >on gcc4 while it's confirmed working on gcc3.
> >(as the noted in the above mail, it looks generating byte access code)
> >
> >Removing __packed might also help, but bus_space(9) just works
> >and it's a right way to go, I think.
> 
> I strongly agree - I've been trying to get our zx driver to work for a  
> while but got sidetracked by other stuff ( mostly sgimips-related ) -  
> thanks for doing this. Writing an accelerated Xorg driver is next on  
> my todo list ( after adding wscons support to zx )

It worked for the console when I checked it in (haven't touched it since).
I think I remember now what SETREG() might have been about. The compiler
was generating sub-word writes, or something along those lines.