RE: Kernel Panic during memcpy_toio to PCI card

["Donepudi, Suneeta" <sdonepudi@3eti.com>]

Hi Dave,

I am not sure if the problem is with memcpy_toio() itself because
I found that the kernel crash occurred even when I replaced the
memcpy_xxio() calls with readl() and writel(). The panic occured
during the memory transfer. We tried looking at the PCI bus
using an analyzer but found nothing wrong.

Thanks,
Suneeta 

-----Original Message-----
From: Dave Jones
To: Matt D. Robinson
Cc: Donepudi, Suneeta; 'linux-kernel@vger.kernel.org'
Sent: 11/1/02 6:29 PM
Subject: Re: Kernel Panic during memcpy_toio to PCI card

On Fri, Nov 01, 2002 at 03:28:10PM -0800, Matt D. Robinson wrote:

 >It still caused the crash in the same manner and at the same location.
 >Could someone help me with pointers to where I should start looking ?
 >Disabling interrupts around the memcpy_toio() did not make any
 >difference. Is this a hardware problem with the PCI card ? We are
using
 >a Xilinx core with out FPGA build into it.

memcpy_toio() in 2.4 is still using memcpy() which could use prefetch()
if you compile for certain processors.  Prefetching io space could do
all sorts of nasties.

2.5 changed this define (in include/asm-i386/io.h) to use __memcpy
instead, which doesn't use prefetching.

		Dave

		Dave

-- 
| Dave Jones.        http://www.codemonkey.org.uk