Critical Interrupt on 405EP

Critical Interrupt on 405EP

[Praveen Mehrotra]

Hello,

I'm running 2.4.20 kernel on a 405EP board and am interested in using
critical interrupt for one of the devices. I've almost got it working,
except that after several minutes (ranging from 10-30) of operation 
kernel crash occurs.

Has anyone got the critical interrupt on 405EP working for 2.4.x
kernels ? I can post details specific to changes I made if someone has
experience regarding this.

Thanks,
Praveen

RE: Critical Interrupt on 405EP

[David Adair]

You might want to check out the old e-mails about CI on the 440.

I use 2.4.19 + some cruft on a 440GP.  In this case
SPRN_SPRG0 and SPRN_SPRG1 are used by both critical and non-critical
interrupts making it just a matter of time before the CI stomps
on a normal interrupt.  You can look at the "PROLOG" stuff in
the appropriate head_xxx.S file to see if you have the same issue.


Have not actually run it, but looking at the code 2.6 is much
closer although. I don't yet understand why crit_transfer_to_handler,
ret_from_crit_exc were not used here though:

#define CRITICAL_EXCEPTION(n, label, hdlr)			\
	START_EXCEPTION(label);					\
	CRITICAL_EXCEPTION_PROLOG;				\
	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
	EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)),
\
			  NOCOPY, transfer_to_handler_full, \
			  ret_from_except_full)

David



> -----Original Message-----
> From: linuxppc-embedded-bounces@ozlabs.org [mailto:linuxppc-embedded-
> bounces@ozlabs.org] On Behalf Of Praveen Mehrotra
> Sent: Wednesday, November 03, 2004 6:09 PM
> To: linuxppc-embedded@ozlabs.org
> Subject: Critical Interrupt on 405EP
> 
> Hello,
> 
> I'm running 2.4.20 kernel on a 405EP board and am interested in using
> critical interrupt for one of the devices. I've almost got it working,
> except that after several minutes (ranging from 10-30) of operation
> kernel crash occurs.
> 
> Has anyone got the critical interrupt on 405EP working for 2.4.x
> kernels ? I can post details specific to changes I made if someone has
> experience regarding this.
> 
> Thanks,
> Praveen
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded