From owner-freebsd-current@FreeBSD.ORG Tue Aug 16 19:12:52 2011 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B12BB106566C; Tue, 16 Aug 2011 19:12:52 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id CA5CE8FC1D; Tue, 16 Aug 2011 19:12:51 +0000 (UTC) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id WAA09541; Tue, 16 Aug 2011 22:12:50 +0300 (EEST) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1QtP4E-000AcT-2J; Tue, 16 Aug 2011 22:12:50 +0300 Message-ID: <4E4AC12F.5010301@FreeBSD.org> Date: Tue, 16 Aug 2011 22:12:47 +0300 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:5.0) Gecko/20110706 Thunderbird/5.0 MIME-Version: 1.0 To: John Baldwin References: <75E1A2A7D185F841A975979B0906BBA67BCC877062@AVEXMB1.qlogic.org> <201108161145.02733.jhb@freebsd.org> <4E4A9A23.7060807@FreeBSD.org> <201108161509.09939.jhb@freebsd.org> In-Reply-To: <201108161509.09939.jhb@freebsd.org> X-Enigmail-Version: 1.2pre Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "freebsd-current@freebsd.org" , David Somayajulu Subject: Re: Loading drivers via kldload X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Aug 2011 19:12:52 -0000 on 16/08/2011 22:09 John Baldwin said the following: > On Tuesday, August 16, 2011 12:26:11 pm Andriy Gapon wrote: >> >> The following are pure speculations, I'd rather let David speak, but just in case; >> >> on 16/08/2011 18:45 John Baldwin said the following: >>> Well, that would seem odd, still. It only returns BUS_PROBE_GENERIC (not 0), so >>> David's driver's probe routine should still be called to get a chance to attach to >>> the device. >> >> Maybe it doesn't do that exactly because device and vendor ID are zeroes as David >> described earlier. > > Eh? device_probe_and_attach()'s loop to probe drivers is not PCI-specific, it > has no idea if a given device is PCI device or not let alone if it has non-zero > subvendor IDs. Also, ata_pci_probe() doesn't look at the subvendor IDs at all. > >>> Also, the ATA driver only allocates its BAR once, so it shouldn't >>> trigger the panic in question in that case (the panic is only triggered when you >>> try to double-allocate a BAR). >> >> This makes only if the BAR has sane values. Not sure what happens if the BAR has >> some junk that duplicates other PCI device, or something like that. > > The panic in question is due to a resource that was reserved by the parent > bus (i.e. either ACPI or PCI) using resource_list_reserve(), then a driver > called resource_list_alloc() on it once successfully, and > resource_list_alloc() is being called a second time to allocate an already- > allocated resource. That won't happen due to junk in a BAR (and BARs are > all standard config header registers anyway). > Thanks for straightening me on both accounts. -- Andriy Gapon