Transfer mode of my ad0 no longer recognized correctly

Radek Kozlowski radek at
Fri Jun 18 20:55:40 GMT 2004

On 2004.06.18 20:45, Radek Kozlowski wrote:
> Hi,
> when using a freshly built -CURRENT kernel (acpi enabled) the transfer 
> mode of my hard disk is set to PIO4 during system init (ad0: 38154MB 
> <IC25N040ATMR04-0> [77520/16/63] at ata0-master PIO4), whereas with a 
> kernel from 28th of May (acpi enabled) it is recognized corretly and set 
> to UDMA100 (ad0: 38154MB <IC25N040ATMR04-0> [77520/16/63] at ata0-master 
> UDMA100). My system's performance is very poor when the disk works in 
> PIO mode, so I'm using my older kernel for now.
> My ata controller:
> atapci0 at pci0:16:0:      class=0x0101b0 card=0x0024103c chip=0x522910b9 
> rev=0xc4 hdr=0x00
>     vendor   = 'Acer Labs Incorporated (ALi)'
>     device   = 'M1543 Southbridge EIDE Controller'
>     class    = mass storage
>     subclass = ATA
> I haven't changed anything in my kernel config file since this last 
> working kernel. Also, when I boot my recent kernel with acpi disabled, 
> the transfer rate is being correctly set to UDMA100.
> When I boot with acpi enabled and try to change the transfer mode manually:
> # atacontrol mode 0 udma100 xxx
> Master = UDMA100
> Slave  = BIOSPIO
> the transfer mode is changed, but I get a kernel panic (fatal trap 12) 
> immediately after that. I wanted to capture a core dump to later on use 
> it with gdb, but I'm unable to produce one. I did everything according 
> to developer's handbook but it's not working:
> # grep dump /etc/rc.conf
> dumpdev="/dev/ad0s1b"
> dumpdir="/usr/crash"
> # swapctl -l
> Device:       1024-blocks     Used:
> /dev/ad0s1b     1048576         0
> # sysctl kern | grep dump
> kern.sugid_coredump: 0
> kern.coredump: 1
> One interesting thing is that there's no such oid as kern.dumpdev 
> (sysctl: unknown oid 'kern.dumpdev') and according to man sysctl there 
> should be one.
> I'll probably take a photo of the output of the trace command in ddb 
> when I get home if I can't get a crash dump.

Here's a photo and also a dmesg:


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