VGA console endian bug
Geert Uytterhoeven
geert at linux-m68k.org
Fri Aug 10 18:41:39 EST 2001
On Thu, 9 Aug 2001, Hollis Blanchard wrote:
> These two patches came from Daniel Berlin on July 9. They completely resolve
> the VGA console backwards-endian problem for me on PPC. If they have Geert's
> seal of approval ;) can they be committed?
>
> -Hollis
>
> --- linuxppc_2_4_devel/include/asm-ppc/vga.h.old Thu Aug 9 11:49:23 2001
> +++ linuxppc_2_4_devel/include/asm-ppc/vga.h Thu Aug 9 11:49:42 2001
> @@ -37,6 +37,9 @@
>
> #define VT_BUF_HAVE_MEMCPYW
> #define scr_memcpyw memcpy
> +#define VT_BUF_HAVE_MEMCPYF
> +#define scr_memcpyw_to memcpy
> +#define scr_memcpyw_from memcpy
>
> #endif /* !CONFIG_VGA_CONSOLE && !CONFIG_MDA_CONSOLE */
The first I cannot approve: if scr_{write,read}w() swap bytes, how can it work
if scr_memcpyw_{to,from}() don't swap bytes?
> --- linuxppc_2_4_devel/drivers/video/fbcon.c.old Thu Aug 9 11:45:10 2001
> +++ linuxppc_2_4_devel/drivers/video/fbcon.c Thu Aug 9 11:46:23 2001
> @@ -2028,13 +2028,13 @@
> if (!conp->vc_can_do_color)
> *p++ ^= 0x0800;
> else if (conp->vc_hi_font_mask == 0x100) {
> - u16 a = *p;
> + u16 a = scr_read(p);
> a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
> - *p++ = a;
> + scr_write(a, p++);
> } else {
> - u16 a = *p;
> + u16 a = scr_read(p);
> a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
> - *p++ = a;
> + scr_write(a, p++);
> }
> if (p == (u16 *)softback_end)
> p = (u16 *)softback_buf;
Approved :-)
And where's the 3rd patch? I once posted a patch to fix a similar bug in
drivers/char/console.c.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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
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