From: Jim Paris <jim@jtan.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [PATCH] Re: time() glitch on 2.4.18: solved
Date: Tue, 5 Nov 2002 11:30:20 -0500 [thread overview]
Message-ID: <20021105113020.A5210@neurosis.mit.edu> (raw)
In-Reply-To: <1036355418.30679.28.camel@irongate.swansea.linux.org.uk>; from alan@lxorguk.ukuu.org.uk on Sun, Nov 03, 2002 at 08:30:18PM +0000
> > Any comments?
>
> Have a play with it, if your idea works when you deliberately disturb it
> then send in a patch
This works well.
-jim
diff -urN linux-2.4.18/arch/i386/kernel/time.c linux-2.4.18-jim/arch/i386/kernel/time.c
--- linux-2.4.18/arch/i386/kernel/time.c Fri Mar 15 18:28:53 2002
+++ linux-2.4.18-jim/arch/i386/kernel/time.c Tue Nov 5 11:22:02 2002
@@ -501,6 +501,16 @@
count = inb_p(0x40); /* read the latched count */
count |= inb(0x40) << 8;
+
+ /* Any unpaired read will cause the above to swap MSB/LSB
+ forever. Try to detect this and reset the counter. */
+ if (count > LATCH) {
+ outb_p(0x34, 0x43);
+ outb_p(LATCH & 0xff, 0x40);
+ outb(LATCH >> 8, 0x40);
+ count = LATCH - 1;
+ }
+
spin_unlock(&i8253_lock);
count = ((LATCH-1) - count) * TICK_SIZE;
next prev parent reply other threads:[~2002-11-05 16:23 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-11-02 6:37 time() glitch on 2.4.18 at 177 days uptime? Jim Paris
2002-11-03 19:32 ` time() glitch on 2.4.18: solved Jim Paris
2002-11-03 20:30 ` Alan Cox
2002-11-05 16:30 ` Jim Paris [this message]
2002-11-05 16:54 ` [PATCH] " george anzinger
2002-11-05 17:10 ` Willy Tarreau
2002-11-05 18:16 ` Alan Cox
2002-11-05 18:02 ` Jim Paris
2002-11-05 18:37 ` Alan Cox
2002-11-05 18:20 ` Willy Tarreau
2002-11-05 18:50 ` Jim Paris
2002-11-05 17:14 ` Willy Tarreau
2002-11-05 17:42 ` Jim Paris
2002-11-05 18:57 ` Richard B. Johnson
2002-11-05 19:08 ` Willy Tarreau
2002-11-05 19:29 ` Richard B. Johnson
2002-11-05 20:07 ` Alan Cox
2002-11-05 20:14 ` Willy Tarreau
2002-11-05 20:38 ` Richard B. Johnson
2002-11-05 23:15 ` Willy Tarreau
2002-11-06 12:47 ` Richard B. Johnson
2002-11-06 13:25 ` Alan Cox
2002-11-06 23:21 ` Jim Paris
2002-11-05 20:23 ` Richard B. Johnson
2002-11-05 20:57 ` Alan Cox
2002-11-05 20:41 ` Richard B. Johnson
2002-11-06 15:09 ` Christer Weinigel
2002-11-06 15:49 ` Richard B. Johnson
2002-11-05 20:06 ` Alan Cox
2002-11-05 17:32 ` Alan Cox
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20021105113020.A5210@neurosis.mit.edu \
--to=jim@jtan.com \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®