From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olof Johansson Subject: ACPI vs DT at runtime Date: Thu, 14 Nov 2013 17:44:10 -0800 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" Cc: Grant Likely , Rob Herring , Arnd Bergmann List-Id: devicetree@vger.kernel.org The more I start to see early UEFI/ACPI code, the more I am certain that we want none of that crap in the kernel. It's making things considerably messier, while we're already very busy trying to convert everything over and enable DT -- we'll be preempting that effort just to add even more boilerplate everywhere and total progress will be hurt. The server guys really want UEFI for their boot protocols, installation managers, etc, etc. That's fine, let them do that, but that doesn't mean we need to bring the same APIs all the way into the kernel. So, I'm strongly urging that whatever the server guys try to do, it will in the end result in the ACPI data being translated into DT equivalents, such that the kernel _only_ needs to handle data via DT. Just like PowerPC scrapes the OpenFirmware client interface to build a flat device tree, we should add a pre-boot stage that scrapes ACPI/UEFI data and constructs an appropriate device-tree. We can still bring over ACPI methods and represent those in the DT, but we should _not_ have two native interfaces. It might be done via having a skeleton/framework DT for the vendor platform that is updated via UEFI/ACPI data, or it might be constructed entirely out of tables coming from firmware. I don't care about the methods for how it is done, but I do feel strongly that we should _not_ introduce a second API for everything. I can't think of a single good reason to do it. [There, commence centithread] -Olof -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: olof@lixom.net (Olof Johansson) Date: Thu, 14 Nov 2013 17:44:10 -0800 Subject: ACPI vs DT at runtime Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The more I start to see early UEFI/ACPI code, the more I am certain that we want none of that crap in the kernel. It's making things considerably messier, while we're already very busy trying to convert everything over and enable DT -- we'll be preempting that effort just to add even more boilerplate everywhere and total progress will be hurt. The server guys really want UEFI for their boot protocols, installation managers, etc, etc. That's fine, let them do that, but that doesn't mean we need to bring the same APIs all the way into the kernel. So, I'm strongly urging that whatever the server guys try to do, it will in the end result in the ACPI data being translated into DT equivalents, such that the kernel _only_ needs to handle data via DT. Just like PowerPC scrapes the OpenFirmware client interface to build a flat device tree, we should add a pre-boot stage that scrapes ACPI/UEFI data and constructs an appropriate device-tree. We can still bring over ACPI methods and represent those in the DT, but we should _not_ have two native interfaces. It might be done via having a skeleton/framework DT for the vendor platform that is updated via UEFI/ACPI data, or it might be constructed entirely out of tables coming from firmware. I don't care about the methods for how it is done, but I do feel strongly that we should _not_ introduce a second API for everything. I can't think of a single good reason to do it. [There, commence centithread] -Olof