Overlapping PCI Memory Locations

[Coleman Kane]

John Baldwin wrote:
> On Friday 07 December 2007 11:21:35 am Coleman Kane wrote:
>   
>> Hi,
>>
>> I've got a problem where two components on my system have overlapping
>> PCI memory regions:
>>
>> atapci0: <ATI ATA controller> port 
>>     
> 0x9000-0x9007,0x9008-0x900b,0x9010-0x9017,0x5018-0x501b,0x5020-0x502f mem 
> 0xd0609000-0xd06093ff irq 16 at device 18.0 on pci0
>   
>> atapci0: [ITHREAD]
>>
>> pcm0: <ATI SB600 High Definition Audio Controller> mem 0xd0608000-0xd060bfff 
>>     
> irq 16 at device 20.2 on pci0
>   
>> pcm0: hdac_mem_alloc: Unable to allocate memory resource
>>
>>
>>
>> Because of this, I cannot use the sound hardware on this system. In
>> addition, the memory range used by atapci0 is the SATA AHCI space. The
>> ata-chipset.c doesn't currently identify the ATI IXP600 SATA controller
>> (just the paired PATA controller), so I can actually use my drives
>> through the PATA/IDE compatibility registers in the I/O space. However,
>> if I modify ata-chipset.c to add support for the IXP600 SATA controller,
>> I get weird results using ATA_INL(..) calls, which look like something
>> is interfering with the data I *should* be getting from the SATA mem space.
>>
>> In addition, the pcm0 refuses to attach, as above.
>>
>> Also, this is a notebook and has one of those crummy notebook BIOSes
>> that don't allow fiddling with this sort of stuff in BIOS. Is there any
>> facility in the kernel to force these to be remapped (or to perform the
>> mappings ourselves and ignore what BIOS tells us)?
>>     
>
> No.  You can hack the pci driver to zero out the BAR in either device during 
> boot though as a test.
>   
What would the kernel do if the BAR were to be zeroed out?

I applied the attached fixup to sys/dev/pci/pci.c that allows me to
specify the desired base address from a loader.conf tunable. Is there a
better way? Is there a project to make a better way?

--
Coleman Kane

-------------- next part --------------
A non-text attachment was scrubbed...
Name: pci.c-hp6715b.diff
Type: text/x-patch
Size: 939 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-hardware/attachments/20071212/47bcda1f/pci.c-hp6715b.bin