From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rajat Jain Date: Fri, 29 Jul 2005 10:23:40 +0000 Subject: Re: Re: Problem while inserting pciehp (PCI Express Hot-plug) driver Message-Id: List-Id: References: <20050725021747.67869.qmail@web34405.mail.mud.yahoo.com> <512afbf905072711295f87ad24@mail.gmail.com> <20050728175217.A1821@unix-os.sc.intel.com> In-Reply-To: <20050728175217.A1821@unix-os.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Rajesh Shah Cc: Kristen Accardi , greg@kroah.com, linux-kernel@vger.kernel.org, linux-newbie@vger.kernel.org, acpi-devel@lists.sourceforge.net, linux-hotplug-devel@lists.sourceforge.net, dkumar@noida.hcltech.com On 7/29/05, Rajesh Shah wrote: > On Thu, Jul 28, 2005 at 07:45:49PM +0900, Rajat Jain wrote: > > > > Okay. I'm sorry but I'm not very clear with this. I'm just putting > > down here my understanding. So basically we have two mutually > > EXCLUSIVE hotplug drivers I can use for PCI Express: > > > A hotplug slot can be controlled only by a single hotplug > technology - pcie shpc or acpiphp. However, different parts of > the I/O hierarchy can be controlled by different technologies. > For example, a host bridge I/O complex can be hotplugged using > acpiphp, but end devices under this IO complex may be hotpplugged > using pcie or shpc hotplug. > > > 1) "pciehp.ko" : We use this PCIE HP driver when our BIOS supports > > Native Hot-plug for PCI Express (which means that hot-plug will be > > handled by OS single handedly). > > > > 2) "acpiphp.ko" : We use this "generic" ACPI HP driver when BIOS > > allows only ITSELF to handle hot-plug events. > > > No, acpi hotplug is not handled by BIOS only. > Both acpi and pcie hotplug need firmware support as well as hardware > support. Hardware in many (but not all) systems support both types of > hotplug and its up to the BIOS to decide which type to support. If the > platform supports pcie hotplug, you see an _OSC & _SUN methods in the > ACPI namespace and the pciehp driver controls hotplug slots. If the > system supports acpi hotplug, you see _ADR and _EJ0 methods in the ACPI > namespace and the acpiphp driver controls the corresponding hotplug slots. > > Rajesh > Thanks a lot. It has proved to be a very useful information for me. I can now do some R&D on it. Thanks again, Rajat ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel