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From: Randy Vinson <rvinson@mvista.com>
To: Edward Hong <edward.qin.hong@gmail.com>
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: kernel ported from ELDK 3.0 hangs (loops in idled()) on my	custom MPC870 Board
Date: Mon, 06 Jun 2005 11:48:32 -0700	[thread overview]
Message-ID: <42A49A80.9000405@mvista.com> (raw)
In-Reply-To: <21fb73bc050605223311af6408@mail.gmail.com>

Edward Hong wrote:
> 
> Yes. rest_init() got called and executed kernel_thread(init,...) ...
> and got into cpu_idle().

Hi Edward,
   I've seen these symptoms before. The problem was traced to external 
interrupts being disabled (MSR[EE] not set). Without external 
interrupts, there is no decrementer interrupt (at least on 7xx 
processors). Without the decrementer, there in no system clock tick and 
without the clock tick, the scheduler won't run which means that the 
init task won't start. To verify that this is the problem, use mfmsr() 
to get the MSR and print it. I'd suggest that you add something like:

     printk("MSR = %x\n", mfmsr());

to rest_init just before call to cpu_idle. Or you can use:

     if (irqs_disabled()) printk(....

if you don't want to decode the MSR yourself.


			Randy Vinson

  parent reply	other threads:[~2005-06-06 18:42 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-06-03 23:10 kernel ported from ELDK 3.0 hangs (loops in idled()) on my custom MPC870 Board Edward Hong
2005-06-04  1:17 ` Wolfgang Denk
2005-06-04 23:40   ` Edward Hong
2005-06-05  0:28     ` Wolfgang Denk
2005-06-06  5:33       ` Edward Hong
2005-06-06  8:03         ` Wolfgang Denk
2005-06-06 18:48         ` Randy Vinson [this message]
2005-06-06 20:00           ` Edward Hong
2005-06-10 21:43             ` Edward Hong

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