From: David Hawkins <dwh@ovro•caltech.edu>
To: Oliver Rutsch <orutsch@sympatec•com>
Cc: linuxppc-embedded@ozlabs•org
Subject: Re: MPC5200, PLX9054 PCI Card - stalled DMA transfers
Date: Fri, 09 Mar 2007 09:03:40 -0800 [thread overview]
Message-ID: <45F1936C.6030008@ovro.caltech.edu> (raw)
In-Reply-To: <45EFBF91.7080304@sympatec.com>
Hi Oliver,
> The PCI card I'm using works without problems on a X86 PC, so I think
> the PLX hardware is O.K. I checked every local PLX9054 register on the
> MPC5200 against the X86 PC. On both computers they have the same values.
Ok, that eliminates a hardware error in reading registers on the board,
i.e., the PCI connection is fine. There could still be errors in
the PCI-9054 local bus connections ...
> Even a simple block DMA does not work, although I checked all registers
> and addresses. So I think the plx driver software is O.K.
I'm sure you have checked this, but I'll mention it just in case ...
you are using readl/writel type functions to access the little-endian
PCI registers from the big-endian PowerPC right?
> on the MPC5200
> and there has to be a hardware reason. Maybe the pci bus is not granted
> to the bus master controller of the PLX9054 when it requests the bus.
> We'll check this when our hardware guy has time for this ;-)
A PCI bus logic analyzer is pretty nice for this type of issue.
I use an Agilent 1680A, and a FuturePlus PCI or CPCI adapter
board. The analyzer is about $20k, while the adapters are about
$2k. However, they pay for themselves pretty quickly.
>> Anyway, manually setup a DMA transfer and convince yourself that
>> you know which bits to twiddle, then figure out why the driver
>> code isn't doing as its asked.
>
> I've done so without success.
Without success on the x86 too?
> The driver seems to make everything correct. A block DMA is fairly
> simple on the 9054, so I think there must be a hardware reason for this.
> Has anybody ever used a PCI card on the MPC5200 which has its own
> busmaster controller? I think most people use the BestComm DMA
> controller on the MPC5200, right?
I tested the PCI debug driver I wrote from an x86 with my PLX
boards, and on a Yosemite (440EP) board. I tested DMA using
the PCI-9054 DMA controllers, and the 440EP controllers.
Read p23 to p35 of my 440EP test document, I have some tests
there that you could repeat ...
http://www.ovro.caltech.edu/~dwh/powerpc_440ep.pdf
However, life will be much easier if you can grab the hardware
guy's logic analyzer ... out of his cold dead hands if need be ;)
Dave
prev parent reply other threads:[~2007-03-09 17:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-01 12:44 MPC5200, PLX9054 PCI Card - stalled DMA transfers Oliver Rutsch
2007-03-01 22:48 ` David Hawkins
2007-03-08 7:47 ` Oliver Rutsch
2007-03-08 12:20 ` Sylvain Munaut
2007-03-09 17:03 ` David Hawkins [this message]
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