From: Kumar Gala <kumar.gala@freescale•com>
To: "Cordes, Aaron M" <aaron.m.cordes@lmco•com>
Cc: <linuxppc-embedded@lists•linuxppc.org>,
"VanBaren, Gerald (AGRE)" <Gerald.VanBaren@smiths-aerospace•com>
Subject: Re: Linux 2.4.27-pre6-bk hangs on MPC8540 board
Date: Fri, 13 Aug 2004 09:30:42 -0500 [thread overview]
Message-ID: <5B4B260B-ED35-11D8-B05C-000393DBC2E8@freescale.com> (raw)
In-Reply-To: <EE7CAF713952AC4A970DD7CD8B4C12A042DCAD@emss09m06.us.lmco.com>
Try just enabling the L1 caches and see if the issue still exists.
- kumar
On Aug 12, 2004, at 5:07 PM, Cordes, Aaron M wrote:
>
> I completely disabled L1 and L2 cache in the processor and I am not
> seeing the memory corruption anymore. So, good news is board is now
> booting, bad news is it's dog slow and we have a memory design to
> debug.
> Thanks to everyone for your prompt and helpful advice.
>
> Aaron
>
>
> -----Original Message-----
> From: VanBaren, Gerald (AGRE)
> [mailto:Gerald.VanBaren@smiths-aerospace•com]
> Sent: Thursday, August 12, 2004 3:32 PM
> To: Cordes, Aaron M
> Subject: RE: Linux 2.4.27-pre6-bk hangs on MPC8540 board
>
>
>
> On 8xx and 82xx and, I presume, 85xx processors, disabling cache
> inhibits burst mode. It is the cache line filling and flushing that
> causes burst accesses. Note that DMA also causes bursts, but that
> becomes a problem much later.
>
> gvb
>
>
>> -----Original Message-----
>> From: owner-linuxppc-embedded@lists•linuxppc.org
>> [mailto:owner-linuxppc-embedded@lists•linuxppc.org]On Behalf Of
>> Cordes, Aaron M
>> Sent: Thursday, August 12, 2004 3:34 PM
>> To: wd@denx•de
>> Cc: linuxppc-embedded@lists•linuxppc.org
>> Subject: RE: Linux 2.4.27-pre6-bk hangs on MPC8540 board
>>
>>
>>
>> Is there a way in Linux or the 8540 to prevent burst accesses, in
>> order to test whether they are the problem? I scanned the processor's
>> reference manual, but I didn't see anything that would let me do this.
>>
>> Thanks
>> Aaron
>>
>> Aaron Cordes
>>
>> -----Original Message-----
>> From: wd@denx•de [mailto:wd@denx•de]
>> Sent: Thursday, August 12, 2004 9:08 AM
>> To: Cordes, Aaron M
>> Cc: linuxppc-embedded@lists•linuxppc.org
>> Subject: Re: Linux 2.4.27-pre6-bk hangs on MPC8540 board
>>
>>
>> In message
>> <EE7CAF713952AC4A970DD7CD8B4C12A042DCA7@emss09m06•us.lmco.com> you
>> wrote:
>>>
>>> We are bringing up an 8540-based board, and are getting hangs at
>>> random spots when booting Linux. Sometimes the hangs occur
>> while the
>>> kernel is initializing, sometimes the boot gets far enough
>> where I can
>>
>>> log in and run a couple of programs. Eventually the board locks up
>>> with no oopses or panics. If I connect to the board with a
>> debugger,
>>> the processor is usually stopped in the Data miss exception handler,
>
>>> and there is usually memory corruption in the kernel code.
>>
>> That's it: memory problems.
>>
>>> I ran memory tests using both Edink and U-boot and they all
>> passed, so
>>
>>> I'm reluctant to blame hardware for the memory corruption.
>> Has anyone
>>
>>> seen similar behavior, or have any suggestions of things I
>> might try?
>>
>> All those memory tests only can test simple read and write accesses;
>> they all fail to access burst mode accesses, which will happen when
>> Linux starts runing, and which are failing.
>>
>> Your SDRAM initialization is bad, and the system crashes when it
>> tries to fetch instructions from RAM. Note that simple read and write
>> accesses may still work, it's the burst mode that is failing.
>>
>> It is NOT sufficient to program the memory controller of your CPU;
>> each SDRAM chip also requires a specific initialization sequence
>> which you must adhere to to the letter - check with the chip
>> manufacturer's manual.
>>
>> Best regards,
>>
>> Wolfgang Denk
>>
>> --
>> Software Engineering: Embedded and Realtime Systems, Embedded Linux
>> Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd@denx•de
>> If this is a service economy, why is the service so bad?
>>
>
>
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2004-08-13 14:30 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-12 22:07 Linux 2.4.27-pre6-bk hangs on MPC8540 board Cordes, Aaron M
2004-08-13 14:30 ` Kumar Gala [this message]
2004-08-14 14:40 ` Chris Zimman
-- strict thread matches above, loose matches on Subject: below --
2004-08-12 22:14 Swarthout Edward L-SWARTHOU
2004-08-12 19:38 Cordes, Aaron M
2004-08-12 22:11 ` Kumar Gala
2004-08-12 22:18 ` Conor McLoughlin
2004-08-12 19:34 Cordes, Aaron M
2004-08-12 12:47 Cordes, Aaron M
2004-08-12 13:09 ` Marc Leeman
2004-08-12 14:07 ` Wolfgang Denk
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