From: Gary R Hook Subject: 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) Date: Tue, 27 Feb 2018 11:45:59 -0600 Message-ID: <6a32bb01-209b-cdf2-093c-fe749627c806@amd.com> References: <20180223223307.18882-1-bigeasy@linutronix.de> <3f0e1a62-a7ea-6d0c-d305-67080803aefd@amd.com> <20180226083508.th2m3xssp36lx3zh@linutronix.de> <372b353d-017d-a72c-b750-9417f6265874@amd.com> <20180227173314.uko5xpf4od2fn74g@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: "Hook, Gary" , linux-crypto@vger.kernel.org, Tom Lendacky , Herbert Xu , Greg Kroah-Hartman , linux-kernel@vger.kernel.org To: Sebastian Andrzej Siewior Return-path: In-Reply-To: <20180227173314.uko5xpf4od2fn74g@linutronix.de> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org 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.