Re: Misbehaving IBM SCSI Disk on XL366

[Jay Estabrook digital com]

>>> Ryan Kirkpatrick said:
> 
> 	I am having an odd problem with an IBM 2GB Fast SCSI disk on my
> XL366 alpha. This disk is being used as a system disk and is connected to
> the onboard NCR53C810 controller. The system is running Debian 2.1 and
> kernel 2.2.7.
> 
> 	Yesterday I installed two Tekram 390 scsi cards and thereby
> switched to the NCR53C8xx driver for all controllers (as recommended by
> the axp-list archives and the kernel help messages). I recompiled a 2.2.7
> kernel with this change and proceeded to boot the sytem. All disks are
> correctly detected on all chains, and this is what the kernel tells me
> about the disk in question:
> 
>    Vendor: IBM       Model: DORS-32160        Rev: WA6A 
>    Type:   Direct-Access                      ANSI SCSI revision: 01 CCS 
> Detected scsi disk sda at scsi0, channel 0, id 1, lun 0 
> ...
> ncr53c810a-0-<1,*>: FAST-10 SCSI 10.0 MB/s (100 ns, offset 8) 
> SCSI device sdb: hdwr sector= 512 bytes. Sectors= 4127761 [2015 MB] [2.0 GB]
> 
> Only, when the system goes to get partition maps for the disks and then
> later load init off of this disk (since it is the system disk), I start
> getting SCSI timeouts on this disk for the onboard scsi chain.

This *may* be the same problem others have seen WRT compiling recent kernels
with EGCS 1.1.2 or later. Try patching the following way, rebuild, and see
if the problem goes away...

--- linux-2.2.12/include/asm-alpha/delay.h	Tue Dec 29 16:56:15 1998
+++ patch-2.2.12/include/asm-alpha/delay.h	Mon Sep 20 14:47:56 1999
@@ -12,9 +12,10 @@
 extern __inline__ void
 __delay(unsigned long loops)
 {
-	__asm__ __volatile__(".align 3\n"
+	__asm__ __volatile__(".align 4\n"
 		"1:\tsubq %0,1,%0\n\t"
-		"bge %0,1b": "=r" (loops) : "0" (loops));
+		"bge %0,1b\n\t"
+		"nop": "=r" (loops) : "0" (loops));
 }

 /*

Good luck.

--Jay++

---------------------------------------------------------------
Jay A Estabrook                       Alpha Engineering - LINUX
Compaq Computer Corp. - MRO1-2/K20    (508) 467-2080
200 Forest Street, Marlboro MA 01752  Jay.Estabrook@compaq.com
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