From: Geert Uytterhoeven <geert@linux-m68k.org>
To: "Gérard Roudier" <groudier@free.fr>
Cc: Linux Kernel Development <linux-kernel@vger.kernel.org>,
Linux/PPC Development <linuxppc-dev@lists.linuxppc.org>
Subject: Sym53c8xx tape corruption squashed! (was: Re: SCSI Tape corruption - update)
Date: Fri, 28 Dec 2001 21:36:05 +0100 (MET) [thread overview]
Message-ID: <Pine.GSO.4.21.0112282115310.277-100000@vervain.sonytel.be> (raw)
In-Reply-To: <Pine.GSO.4.21.0112051628480.5865-100000@mullein.sonytel.be>
On Wed, 5 Dec 2001, Geert Uytterhoeven wrote:
> On Fri, 2 Nov 2001, [ISO-8859-1] Gérard Roudier wrote:
> > On Thu, 1 Nov 2001, Geert Uytterhoeven wrote:
> > As driver sym-2 is planned to replace sym53c8xx in the future, it would be
> > interesting to give it a try on your hardware. There are some source
> > available from ftp.tux.org, but I can provide you with a flat patch
> > against the stock kernel version you want. You may let me know.
>
> I tried sym-2 (2.4.17-pre2) and it didn't show up the problem, which is good!
>
> More news from the old driver:
>
> 1.5c OK
> 1.5d OK
> 1.5e page fault in interrupt handler 0xa53c0c68
> 1.5f lock up
> 1.5pre-g1 lock up
> 1.5pre-g2 lock up
> 1.5pre-g3 corruption
> 1.5g corruption
>
> So it happened somewhere in between 1.5d and 1.5pre-g3. I'll see whether I can
> get any of the intermediates to run...
I made all intermediate versions to work.
The problem is introduced in 1.5pre-g2 by the following change:
diff -urN callisto-1.5g-pre2a/sym53c8xx.c callisto-1.5g-pre2+/sym53c8xx.c
--- callisto-1.5g-pre2a/sym53c8xx.c Fri Dec 28 21:12:30 2001
+++ callisto-1.5g-pre2+/sym53c8xx.c Fri Dec 28 20:11:10 2001
@@ -11981,7 +11981,7 @@
** (latency timer >= burst length + 6, we add 10 to be quite sure)
*/
- if ((pci_fix_up & 4) && chip->burst_max) {
+ if (chip->burst_max && (latency_timer == 0 || (pci_fix_up & 4))) {
uchar lt = (1 << chip->burst_max) + 6 + 10;
if (latency_timer < lt) {
printk(NAME53C8XX
This change causes the PCI latency timer to be changed from 0 to 80.
The sym-2 driver has a define for modifying the PCI latency timer
(SYM_SETUP_PCI_FIX_UP), but it is never used, so I see no corruption.
Is this a hardware bug in my SCSI host adapter (53c875 rev 04) or my host
bridge (VLSI VAS96011/12 Golden Gate II for PPC), or a software bug in the
driver (wrong burst_max)?
To recapitulate, the bug causes error bursts of (almost always) 32 bytes long.
The incorrect bytes are always a copy of previous data, at a fixed offset (10
kiB on my (now dead) DDS-1 tape drive, 32 kiB on my Plexwriter).
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
next prev parent reply other threads:[~2001-12-28 20:36 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-05-07 14:46 SCSI Tape corruption - update Lorenzo Marcantonio
2001-05-07 15:39 ` Rob Turk
2001-05-07 19:15 ` Lorenzo Marcantonio
2001-05-08 7:12 ` Geert Uytterhoeven
2001-05-08 8:16 ` Lorenzo Marcantonio
2001-06-21 9:33 ` Geert Uytterhoeven
2001-07-08 13:33 ` Geert Uytterhoeven
2001-07-08 19:01 ` Gérard Roudier
2001-07-20 17:08 ` Geert Uytterhoeven
2001-07-20 21:02 ` Gérard Roudier
2001-07-27 7:49 ` Geert Uytterhoeven
2001-07-27 20:41 ` Gérard Roudier
2001-07-28 9:57 ` Geert Uytterhoeven
2001-11-01 19:09 ` Geert Uytterhoeven
2001-11-02 7:04 ` Gérard Roudier
2001-11-07 15:26 ` Geert Uytterhoeven
2001-12-05 15:32 ` Geert Uytterhoeven
2001-12-28 20:36 ` Geert Uytterhoeven [this message]
2001-12-29 0:57 ` Sym53c8xx tape corruption squashed! (was: Re: SCSI Tape corruption - update) Gérard Roudier
2001-12-29 10:49 ` Geert Uytterhoeven
2001-12-29 13:23 ` Geert Uytterhoeven
2001-12-29 18:39 ` Gérard Roudier
2001-12-29 21:28 ` Geert Uytterhoeven
2001-12-30 0:00 ` Gérard Roudier
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