[PATCH] drivers/misc/cxl: Avoid unnecessary error message

Michael Ellerman mpe at ellerman.id.au
Tue Feb 7 22:12:48 AEDT 2017

Andrew Donnellan <andrew.donnellan at au1.ibm.com> writes:

> On 31/01/17 14:43, Gavin Shan wrote:
>> The following error message was observed. It's complaining M32
>> memory window is missed on virtual PHB, which is a bit confusing.
>> The problem is the memory windows are never updated from its
>> device-tree node.
>>    PCI: Memory resource 0 not set for host bridge \
>>    /pciex at 3fffe40000000/pci at 0/device at 0
>> This avoids the unnecessary error message by updating the PHB's
>> memory windows with pci_process_bridge_OF_ranges(). The function
>> is exported as well.
>> Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
> I talked this over with Gavin in person today.
> We don't set a memory window on the vPHB or its devices because it's not 
> necessary.
> The effect of this patch is to copy the memory resources from the *real* 
> PHB to the vPHB, as given through the device tree. It shouldn't have any 
> practical effect other than squashing this message.

It sounds a bit backward to me. If we don't need the resources then
why have them?

If we have code that thinks that's an error, than maybe that's what
needs fixing, or special casing for the vPHB?


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