Re: Can a driver->probe be called for two devices at the same time (WAS: Re: [PATCH] crypto/ccp: don't disable interrupts while setting up debugfs)

From: Gary R Hook
Date: Tue Feb 27 2018 - 12:46:16 EST


On 02/27/2018 11:33 AM, Sebastian Andrzej Siewior wrote:
On 2018-02-27 11:08:56 [-0600], Gary R Hook wrote:
That issue remains unclear to me: Are probes of PCI devices guaranteed to be
serialized? Observations on my CCPs says that they occur in order, but I
don't know for certain that serialization is guaranteed.

Is there a definitive statement on this somewhere that I just don't know
about?

So the question if a driver can probe two devices simultaneously. I'm
not sure. We have PROBE_PREFER_ASYNCHRONOUS which defers the probe to
worker. However I have no idea if two of those worker can run at the
same time.

I think a mutex would be just fine; I got this wrong, clearly. Let me work
up a patch using a mutex.

I've sent one. Why not just ack it and be done with it?

Gary

Sebastian


Sorry, too much chaos right now. Of course.