On Sun, Aug 03, 2014 at 01:53:56PM +0200, Maxime Ripard wrote: > Hi, > > You forgot to Cc the linux-arm-kernel mailing-list and Emilio.
This was deliberate, as the contents of the patch is still controversial. > That looks wrong. Why doesn't simplefb claim the clocks itself? The code up there uses clock names, and a set of three names which requires the code to know which clocks are needed to make u-boot happy. This is fundamentally wrong, as it spreads the u-boot graphics driver over both u-boot and the kernel, and this sort of detachment and lack of segmentation is totally unacceptable. So, to have simplefb claim these clocks, as is, simplefb would need to know the names of the relevant clocks. Adding platform and u-boot version specific code to the simplefb driver directly is even more fundamentally wrong. The solution for that is to have u-boot create the list of relevant clocks in the dt node for simplefb. Which then runs straight into the clocks being referenced as <&label register-bit-offset>, and the whole discussion around that again. As stated, i will be working on writing up the code for that, and it will nicely show how contrived this is. Time will further show how the lack of abstraction with respect to clocks will come back to bite us. The most obvious sign is that our clock code is spread over 3 places: * once in the dts, to have other nodes claim the clock, by <&label register-bit offset> * once in the dts where the clock register is given a list of bit names but no bit definitions. * once in the clock driver where bitmasks exist (but no names) which must match the list of names in the dts perfectly. If simplefb not claiming the clocks felt fundamentally wrong, then the above should've made your hair stand on end. It is pure luck that that works today, but that sort of luck will run out very quickly. Luc Verhaegen. -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
