VIA 686 timer bugfix incomplete

From: Jonas Diemer <diemer@gmx.de>
To: Linux Kermel ML <linux-kernel@vger.kernel.org>
Subject: VIA 686 timer bugfix incomplete
Date: Wed, 7 Nov 2001 12:50:12 +0100	[thread overview]
Message-ID: <20011107125012.6b1fbdc3.diemer@gmx.de> (raw)

HI!

I noticed with great happiness that the via timer bugfix had made it into linus'
version of the kernel as of 2.4.10.

but it seems that the patch was incomplete: The bug is still triggered on my
computer using 2.4.14, but the bugfix seems to work whith -ac kernels.
 

now I diffed the ac-version of that file whith the current version of linus'
kernel:

# diff -u arch/i386/kernel/time.c ../linux-2.4.10-ac12/arch/i386/kernel/time.c

--- arch/i386/kernel/time.c     Wed Oct 24 17:16:13 2001
+++ ../linux-2.4.10-ac12/arch/i386/kernel/time.c        Sun Oct 14 16:23:52 2001
@@ -501,6 +501,24 @@
 
                count = inb_p(0x40);    /* read the latched count */
                count |= inb(0x40) << 8;
+
+
+                /* VIA686a test code... reset the latch if count > max */
+                if (count > LATCH) {
+                        static int last_whine;
+                        outb_p(0x34, 0x43);   
+                        outb_p(LATCH & 0xff, 0x40);
+                        outb(LATCH >> 8, 0x40);
+                        count = LATCH - 1;
+                        if(time_after(jiffies, last_whine))
+                        {
+                                printk(KERN_WARNING "probable hardware bug:
clock timer configuration lost - probably a VIA686a motherboard.\n");
+                                printk(KERN_WARNING "probable hardware bug:
restoring chip configuration.\n");
+                                last_whine = jiffies + HZ;
+                        }                       
+                }                               
+
+
                spin_unlock(&i8253_lock);
 
                count = ((LATCH-1) - count) * TICK_SIZE;


you can see what's missing to actually work around the via timer bug. I hope
this will go into 2.4.15.

regards

PS: CC me in your answers, I am not subscribed to the list
