microcode_ctl input/output error

[Choo Zhi Min]

Hi,

I am using Fedora 1, kernel 2.4.22-1.2129.nptlsmp. Dual Xeon 2.8Ghz.

# /sbin/microcode_ctl -u
/sbin/microcode_ctl: writing microcode (length: 141312)
/sbin/microcode_ctl: error writing to '/dev/cpu/0/microcode' errno=5 
(Input/output error)
/sbin/microcode_ctl: there may be messages from the driver in your system 
log.

But 'cat /var/log/messages' immediately after the above line does not 
contain any microcode_ctl related error messages. The microcode used is 
/etc/firmware/microcode.dat.

Durnig bootup, the screen shows "Applying Intel IA32 Microcode update: [  
OK  ]". But it is actually an error, because the startup script use -Q 
switch (run silently even on failure).

For now I have disabled applying microcode at startup. Is it important to 
apply microcode? Any fix to this error?
Thanks!


Regards,
Zhi Min



PS: Some info, if it helps:

# ll /dev/cpu/0/microcode
crw-------    1 root     root      10, 184 Sep 15 21:40 
/dev/cpu/0/microcode

# cat /dev/cpu/0/microcode
<nothing shows up>

# cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 2
model name      : Intel(R) Xeon(TM) CPU 2.80GHz
stepping        : 9
cpu MHz         : 2786.401
cache size      : 512 KB
physical id     : 0
siblings        : 2
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca 
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe cid
runqueue        : 0

bogomips        : 5557.45
<snip>