From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Glass Date: Mon, 20 Jul 2015 08:25:13 -0600 Subject: [U-Boot] [PATCH 00/20] arm: rpi: Enable USB and Ethernet driver model Raspberry Pi In-Reply-To: <20150716141009.GC29918@amd> References: <1436324032-17931-1-git-send-email-sjg@chromium.org> <55A0AAD3.2050302@wwwdotorg.org> <55A495AA.6080609@wwwdotorg.org> <20150716141009.GC29918@amd> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Stephen, On 16 July 2015 at 08:10, Pavel Machek wrote: > On Mon 2015-07-13 22:52:58, Stephen Warren wrote: >> On 07/11/2015 08:04 AM, Simon Glass wrote: >> > Hi Stephen, >> > >> > On 10 July 2015 at 23:34, Stephen Warren wrote: >> >> On 07/07/2015 08:53 PM, Simon Glass wrote: >> >>> Raspberry Pi uses a DWC2 USB controller and a SMSC USB Ethernet adaptor. >> >>> Neither of these currently support driver model. >> >>> >> >>> This series does the following: >> >>> - Move Raspberry Pi to use device tree control (u-boot-dtb.bin instead of >> >>> u-boot.bin) >> >> >> >> I'd strongly prefer not to do this. For one thing, it means we'd need >> >> different U-Boot builds for each of the different RPi models, and we >> >> currently don't need that (or perhaps we require users to create their >> >> own u-boot-dtb.bin by choosing the right DTB to append). If it >> > >> > Why does device tree change how things work now? The get_board_rev() >> > function currently deals with this. It doesn't look like rpi_board_rev >> > is used anywhere else. >> >> Without a DT, the code is free to make all the board-rev-specific >> decisions at run-time without external influence. >> >> With a DT, we either have to: >> >> a) Pick the DT for one particular board and use that everywhere, even if >> it's incorrect for the actual board in use. > > Is that an option? I mean... if you can tolerate incorrect values for > something, perhaps that something should not be in the dtb in the > first place? > >> b) Build a different U-Boot + DTB image for each board-rev, and put the >> correct one on the SD card. > > d) Build U-Boot + set of DTB images, then pick up the right one at the > runtime? > >> Neither of those options seem like a good idea to me. > > Stuff that can be autodetected does not belong to the device tree... > > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html Stephen please can you update here? It seems to me that there is no requirement to add a lot of stuff to the device tree which we already have code to auto-detect. I'd like to pull in these changes but can hold off on the rpi parts until we figure this out. Regards, Simon