Subject: Re: mmap'ing framebuffer memory in MI drivers...
To: Jonathan Stone <jonathan@DSG.Stanford.EDU>
From: Chris G. Demetriou <email@example.com>
Date: 03/03/1999 13:19:45
Jonathan Stone <jonathan@DSG.Stanford.EDU> writes:
> >I will assert (again) that mapping the device registers is an inherently
> >bus-specific operation and should be done by the driver through the use of
> >bus_space*() routines rather than the VM system.
> Agreed. What I'm saying is that that after a bus_space_mmap() has done
> its thing, then converting the ``system physical address'' it returns
> to a (*d_mmap)() entrypoint is an MD operation. if we want MI drivers
> for mmap'able devices we need an MI hook to do that conversion; end of
Except, it should _not_ return a "system physical address," it should
return whatever needs to be returned from mmap() for that
architecture. that's kinda the whole point.
(there's no reason that _i_ can think of to insert Yet Another MD
Operation there; it's _already_ an MD operation.)
Chris Demetriou - firstname.lastname@example.org - http://www.netbsd.org/People/Pages/cgd.html
Disclaimer: Not speaking for NetBSD, just expressing my own opinion.