From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752169AbWCCDj4 (ORCPT ); Thu, 2 Mar 2006 22:39:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752105AbWCCDj4 (ORCPT ); Thu, 2 Mar 2006 22:39:56 -0500 Received: from mailhub.hp.com ([192.151.27.10]:31945 "EHLO mailhub.hp.com") by vger.kernel.org with ESMTP id S1752093AbWCCDjz (ORCPT ); Thu, 2 Mar 2006 22:39:55 -0500 Message-ID: <1084.24.9.204.52.1141357193.squirrel@mail.atl.hp.com> In-Reply-To: References: <200603022340.k22Neq0o014875@shell0.pdx.osdl.net> Date: Thu, 2 Mar 2006 20:39:53 -0700 (MST) Subject: Re: + pnp-mpu401-adjust-pnp_register_driver-signature.patch added to -mm tree From: "Bjorn Helgaas" To: "Eric W. Biederman" Cc: linux-kernel@vger.kernel.org, bjorn.helgaas@hp.com, ambx1@neo.rr.com, mm-commits@vger.kernel.org User-Agent: SquirrelMail/1.4.4 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Priority: 3 (Normal) Importance: Normal Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >> This series of patches removes the assumption that pnp_register_driver() >> returns the number of devices claimed. Returning the count is >> unreliable >> because devices may be hot-plugged in the future. (Many devices don't >> support >> hot-plug, of course, but PNP in general does.) > > Huh? > > How do onboard devices or ISA plug and play devices support hot-plug? > > Or what devices supported by the pnp subsystem support hot-plug? I don't know for sure whether ISAPNP or PNPBIOS support hot-plug, but ACPI does, and ACPI devices are being integrated into the PNP subsystem via PNPACPI. One example is HP sx2000 hardware that supports hot-plug of cells. Each cell contains CPUs, memory, I/O bridges, and some miscellaneous hardware like on-board serial devices. All this stuff is described by ACPI, and we'd like to use PNP drivers like 8250_pnp.c when we can.