Re: driver skip pci_set_master, fix it? No.

From: Mark Lord
Date: Wed Apr 09 2014 - 09:09:00 EST


On 14-04-08 10:51 PM, Benjamin Herrenschmidt wrote:
> On Tue, 2014-04-08 at 17:18 -0400, Mark Lord wrote:
>>> I assume you're talking about the one added by cf3e1feba7f9 ("PCI:
>>> Workaround missing pci_set_master in pci drivers"), but as far as I
>>> can tell, it only calls pci_set_master() for *bridge* devices. What
>>> am I missing? Is pci_set_master() being called for your endpoint?
>>> What path is that?
>>
>> Yes, it is being called during execution of the _probe() function in my driver,
>> as evidenced by the annoying (and wrong) message it produces.
>>
>> Next time I've got the hardware at hand, I'll put a "dump_stack()" into there
>> to see the exact calling path.
>
> Note that one of the reason we want to do it early on bridges is that without it,
> we may also not get the PCIe error messages.

Sure, for bridges.

I'll get a stack trace later today, but what I suspect is happening
is that this multi-function card is being treated by the PCI layers
as a "bridge" for purposes of the multiple virtual functions it implements.

We will probably need to distinguish this kind of device from real bridges here.
--
Mark Lord
Real-Time Remedies Inc.
mlord@xxxxxxxxx
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