On Tue, Jan 17, 2017 at 02:36:50PM +1100, Thomas Petazzoni wrote: > Hello, > > (Side note: you guys should learn about stripping irrelevant parts of > an e-mail when replying!) > > On Mon, 16 Jan 2017 09:40:32 +0100, Boris Brezillon wrote: > > > > Well this is OK I guess, but then you can also use "mediatek,mt8173-nor" > > > as the oldest supported compatible and be done with it, no ? It looks a > > > bit crappy though, I admit that ... > > > > Let's stop bikeshedding and wait for DT maintainers feedback > > before taking a decision ;-). > > > > Rob, Mark, any opinion? > Sigh, is how to do compatibles really not yet understood? > I agree that a clarification would be good. There are really two > options: > > 1. Have two compatible strings in the DT, the one that matches the > exact SoC where the IP is found (first compatible string) and the > one that matches some other SoC where the same IP is found (second > compatible string). Originally, Linux only supports the second > compatible string in its device driver, but if it happens that a > difference is found between two IPs that we thought were the same, > we can add support for the first compatible string in the driver, > with a slightly different behavior. This. And no wildcards in the compatible string. > 2. Have a single compatible string in the DT, matching the exact SoC > where the IP is found. This involves adding immediately this > compatible string in the corresponding driver. I wouldn't object to this from a DT perspective as I have no clue generally if IP blocks are "the same" or not. Subsystem maintainers will object though. > I've not really been able to figure out which of the two options is the > most future-proof/appropriate. They are both future-proof. #2 has the disadvantage of requiring a kernel update for a new SoC. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
