Re: [Linux-fbdev-devel] why does radeonfb work fine in 2.6, but not in 2.4.29-pre1?

[Jurriaan <thu...@xs...>]

From: Kronos <kr...@pe...>
Date: Mon, Nov 29, 2004 at 10:35:10PM +0100
> Il Sun, Nov 28, 2004 at 07:46:06PM +0100, Jurriaan ha scritto: 
> > The same radeonfb-setup works fine in every 2.6 kernel I can remember
> > (last tested with 2.6.10-rc2-mm3) but give the dreaded 'cannot map FB'
> > in 2.4.29-pre1.
> > 
> > The card has 128 Mb of ram, and my system has 3 Mb of RAM.
> > 
> > Is there any reason the ioremap() call works on 2.6, but doesn't on 2.4?
> 
> Driver in 2.6 only ioremap()s the memory needed for the framebuffer,
> while the one in 2.4 ioremap()s all the VRAM (and fails).
> 
> > Is there any way to test 2.4 with my radeonfb and all of my memory?
> 
> I proposed the following patch some time ago (for 2.4.28-pre2 IIRC) as a
> quick fix:
> 
Thanks. I found that patch on google. Problem is: when I look through
the radeonfb in 2.6, I don't see any assignments to rinfo->video_ram
that indicate it maps less than the full amount.

> 
> Problem is that fix->smem_len is used both by FBIOGET_FSCREENINFO to
> report the amount of VRAM to userspace and by read/write/mmap on fb
> for bounds checking. So with my patch FBIOGET_FSCREENINFO reports mapped
> VRAM instead of physical VRAM.
> 
> smem_len should be splitted in (say) smem_mapped (for read/write/mmap)
> and smem_total_vram (for FBIOGET_FSCREENINFO). I'll code something
> tomorrow... -ENEEDSLEEP ;)
> 
Thanks,
Jurriaan
-- 
All wiyht. Rho sritched mg kegtops awound?
Debian (Unstable) GNU/Linux 2.6.10-rc2-mm3 2x6078 bogomips load load 0.24