Re: [PATCH 2/2] m68k/atari - atafb: convert allocation of fb ram to new interface

Geert Uytterhoeven
2014-03-19T08:01:21Z

On Wed, Mar 19, 2014 at 8:23 AM, Michael Schmitz <schmitzmic@gmail.com> wrote:
> @@ -3166,7 +3166,7 @@ int __init atafb_init(void)
> memset(screen_base, 0, mem_req);
> pad = -(unsigned long)screen_base & (PAGE_SIZE - 1);
> screen_base += pad;
> - real_screen_base = screen_base + ovsc_offset;
> + real_screen_base = atari_stram_to_phys((unsigned long) (screen_base + ovsc_offset));

This triggered my eye, but it's actually correct, as it's stored in
fix->smem_start,
which should be the physical address.

But the external_addr case is wrong ;-)

> screen_len = (mem_req - pad - ovsc_offset) & PAGE_MASK;
> st_ovsc_switch();
> if (CPU_IS_040_OR_060) {

Starting here, you have:

cache_push(virt_to_phys(screen_base), screen_len);

atari_stram_to_phys()

kernel_set_cachemode(screen_base, screen_len,
IOMAP_WRITETHROUGH);

woops, that won't work with the virt_to_phys() above, nor with transparent
translation. I guess it writes to a non-existent pointer table,
causing the crash?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds