From: Pantelis Antoniou <panto@intracom•gr>
To: robin.gilks@tait•co.nz
Cc: ppc embedded list <linuxppc-embedded@ozlabs•org>
Subject: Re: 8xx bus monitoring
Date: Mon, 31 Jan 2005 09:09:23 +0200 [thread overview]
Message-ID: <41FDD9A3.9040604@intracom.gr> (raw)
In-Reply-To: <41FD5C91.404@tait.co.nz>
Robin Gilks wrote:
> Pantelis Antoniou wrote:
>
>> Robin Gilks wrote:
>>
>>> Greetings
>>>
>>> System is a MPC859 based controller.
>>>
>>> I'm trying to determine whether a peripheral is not responding to
>>> memory fetches by using the bus monitor feature on the Transfer
>>> Acknowledge (TA) signal. This is set to the maximum count in the Bus
>>> Monitor Timeout (BMT) in the System Protect Control Register (SYPCR).
>>> The monitoring is enabled by setting the Bus Monitor Enable (BME) bit
>>> in SYPCR as well.
>>>
>>> I understand that I can use the Transfer Error Status Register (TESR)
>>> to read the fact that I have had a timeout by checking the Data
>>> Transfer Monitor Timeout (DTMT) bit in this register.
>>>
>>> The problem is, how do I know any error has occured so I know to look
>>> at the TESR. I can't see a way of generating an exception from this
>>> condition.
>>>
>>> Any help appreciated.
>>>
>>
>> You get a machine check exception.
>>
>> It's pretty obvious then :)
>>
>
> Using a 2.4.22 based kernel, as far as I can see a machine check should
> be trapped (its only allowed to cause a reset in the reboot code I
> think). Assuming I got it right and it really is trapped, how come I
> always get a reset:-((
>
> Any pointers to the code that does setup for causing an exception
> (rather than reset) would be appreciated.
>
Check the MSR register at the time of the access.
Is RI set? If not instead of an exception you get a reset...
Regards
Pantelis
next prev parent reply other threads:[~2005-01-31 7:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-01-26 2:31 8xx bus monitoring Robin Gilks
2005-01-26 7:06 ` Pantelis Antoniou
2005-01-30 22:15 ` Robin Gilks
2005-01-31 7:09 ` Pantelis Antoniou [this message]
2005-01-31 21:49 ` Robin Gilks
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