Re: ohci1394 problem (MMIO broken) (was 2.6.25-rc6-git6: Reportedregressions from 2.6.24)

From: Ingo Molnar
Date: Sun Mar 23 2008 - 02:36:28 EST



* Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx> wrote:

> On my x86-32 test system, none of the devices gets an MMIO region
> above the 4G map. (Reconfigured with CONFIG_RESOURCES_64BIT=y while
> having CONFIG_HIGHMEM4G=y, like in Thomas M's .config.)

64-bit ioremap on x86 never worked AFAIK, the whole API is using 32-bit
physical addresses which is limited to 4GB. But ... this bug does have
the feeling of the wrong IO side physical memory being mapped. (0xff
data means there's no device there - typical of non-existent RAM/IO)

could you please pull the x86/latest tree to do a kernel pagetable dump
for us? You can pull it via the instructions here:

http://people.redhat.com/mingo/x86.git/README

then enable CONFIG_DEBUG_KERNEL=y and CONFIG_X86_PTDUMP=y boot the
kernel so that ohci1394 doesnt work. Then dump the pagetables and other
hw info via:

http://people.redhat.com/mingo/cfs-scheduler/tools/cfs-debug-info.sh

send us the cfs-debug-info file that gets generated. We'll be able to
tell from that whether your ioremap's are OK. (x86/latest will also
printk all ioremap()s and results that are done)

thanks,

Ingo
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