From: Daniel Jacobowitz <drow@false.org>
To: Benjamin Herrenschmidt <bh40@calva.net>,
Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linuxppc-dev@lists.linuxppc.org
Subject: Re: controlfb.c bug in VRAM bank2 check if bank1
Date: Sun, 12 Sep 1999 14:10:14 -0400 [thread overview]
Message-ID: <19990912141014.A17732@them.org> (raw)
In-Reply-To: <19990911112323.032168@smtp.calvacom.fr>; from Benjamin Herrenschmidt on Sat, Sep 11, 1999 at 11:23:23AM +0200
[-- Attachment #1: Type: text/plain, Size: 1110 bytes --]
OK, this patch should d the trick.
On Sat, Sep 11, 1999 at 11:23:23AM +0200, Benjamin Herrenschmidt wrote:
> >I have a bunch of information on this lying around, and most of my
> >other kernel problems seem to be resolved now. I'm in the process of
> >upgrading to current vger; if it succeeds, I'll try to merge all
> >pending controlfb stuff tomorrow.
>
> I also have a pair of crazy 8500 who have 2Mb of VRAM but in bank2 (they
> don't work if the VRAM is moved to bank1, even under MacOS). The current
> controlfb appears to work well. Send me your merge results, I'll test on
> one of those weird machines Monday.
>
>
> --
> E-Mail: <mailto:bh40@calva.net>
> BenH. Web : <http://calvaweb.calvacom.fr/bh40/>
>
>
>
>
Dan
/--------------------------------\ /--------------------------------\
| Daniel Jacobowitz |__| SCS Class of 2002 |
| Debian GNU/Linux Developer __ Carnegie Mellon University |
| dan@debian.org | | dmj+@andrew.cmu.edu |
\--------------------------------/ \--------------------------------/
[-- Attachment #2: control.diff --]
[-- Type: text/plain, Size: 2778 bytes --]
Index: controlfb.c
===================================================================
RCS file: /cvs/linux/linux/drivers/video/controlfb.c,v
retrieving revision 1.20
diff -u -r1.20 controlfb.c
--- controlfb.c 1999/09/10 07:04:03 1.20
+++ controlfb.c 1999/09/12 18:03:57
@@ -702,26 +702,48 @@
p->cmap_regs = ioremap(p->cmap_regs_phys, 0x1000);
/* Work out which banks of VRAM we have installed. */
- /* danj: I guess the card just ignores writes to nonexistant VRAM... */
+ /* According to Andrew Fyfe <bandr@best.com>, the VRAM behaves like so: */
+ /* afyfe: observations from an 8500:
+ * - with 2M vram in bank 1, it appears at offsets 0, 2M and 4M
+ * - with 2M vram in bank 2, it appears only at offset 6M
+ * - with 4M vram, it appears only as a 4M block at offset 0.
+ */
+
+ /* We know there is something at 2M if there is something at 0M. */
+ out_8(&p->frame_buffer[0x200000], 0xa5);
+ out_8(&p->frame_buffer[0x200001], 0x38);
+ asm volatile("eieio; dcbi 0,%0" : : "r" (&p->frame_buffer[0x200000]) : "memory" );
+
out_8(&p->frame_buffer[0], 0x5a);
out_8(&p->frame_buffer[1], 0xc7);
asm volatile("eieio; dcbi 0,%0" : : "r" (&p->frame_buffer[0]) : "memory" );
- bank1 = (in_8(&p->frame_buffer[0]) == 0x5a) && (in_8(&p->frame_buffer[1]) == 0xc7);
- out_8(&p->frame_buffer[0x600000], 0xa5);
- out_8(&p->frame_buffer[0x600001], 0x38);
- asm volatile("eieio; dcbi 0,%0" : : "r" (&p->frame_buffer[0x600000]) : "memory" );
- bank2 = (in_8(&p->frame_buffer[0x600000]) == 0xa5)
- && (in_8(&p->frame_buffer[0x600001]) == 0x38);
-
- p->total_vram = (bank1 + bank2) * 0x200000;
- /* If we don't have bank 1 installed, we hope we have bank 2 :-) */
- p->control_use_bank2 = !bank1;
- if (p->control_use_bank2) {
+ bank1 = (in_8(&p->frame_buffer[0x000000]) == 0x5a)
+ && (in_8(&p->frame_buffer[0x000001]) == 0xc7);
+ bank2 = (in_8(&p->frame_buffer[0x200000]) == 0xa5)
+ && (in_8(&p->frame_buffer[0x200001]) == 0x38);
+
+ if(bank2 && !bank1)
+ printk(KERN_INFO "controlfb: Found memory at 2MB but not at 0! Please contact dan@debian.org\n");
+
+ if(!bank1) {
+ out_8(&p->frame_buffer[0x600000], 0xa5);
+ out_8(&p->frame_buffer[0x600001], 0x38);
+ asm volatile("eieio; dcbi 0,%0" : : "r" (&p->frame_buffer[0x600000]) : "memory" );
+ bank2 = (in_8(&p->frame_buffer[0x600000]) == 0xa5)
+ && (in_8(&p->frame_buffer[0x600001]) == 0x38);
+ /* If we don't have bank 1 installed, we hope we have bank 2 :-) */
+ p->control_use_bank2 = 1;
p->frame_buffer += 0x600000;
p->frame_buffer_phys += 0x600000;
}
+ p->total_vram = (bank1 + bank2) * 0x200000;
+
+ printk(KERN_INFO "controlfb: Memory bank 1 %s, bank 2 %s, total VRAM %dMB\n",
+ bank1 ? "present" : "absent", bank2 ? "present" : "absent",
+ 2 * (bank1 + bank2));
+
init_control(p);
}
next prev parent reply other threads:[~1999-09-12 18:10 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-09-10 15:55 controlfb.c bug in VRAM bank2 check if bank1 Lou Langholtz
1999-09-10 17:08 ` Lou Langholtz
1999-09-10 18:33 ` Michel Lanners
1999-09-12 16:58 ` Lou Langholtz
1999-09-13 18:13 ` Michel Lanners
1999-09-15 15:14 ` Lou Langholtz
1999-10-12 7:07 ` Lou Langholtz
1999-10-12 7:23 ` Bizarre g++ problem Patrik Jonsson
1999-10-12 6:49 ` controlfb.c bug in VRAM bank2 check if bank1 Lou Langholtz
1999-10-12 14:50 ` Daniel Jacobowitz
1999-10-12 15:36 ` Lou Langholtz
1999-10-13 6:30 ` Geert Uytterhoeven
1999-09-11 10:51 ` Brad Boyer
1999-09-10 20:13 ` Daniel Jacobowitz
1999-09-11 9:23 ` Benjamin Herrenschmidt
1999-09-12 18:10 ` Daniel Jacobowitz [this message]
-- strict thread matches above, loose matches on Subject: below --
1999-09-15 17:05 Kevin_Hendricks
1999-09-15 18:26 ` Kevin Puetz
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