> From: Marco Felsch [mailto:m.felsch@xxxxxxxxxxxxxx] > Sent: Wednesday, February 20, 2019 4:17 PM > On 19-02-20 03:38, Aisheng Dong wrote: > > [...] > > > > > > I don't like droping some ID's (e.g. IMX_SC_R_DC_0_CAPTURE0) by > > > > mark them as unused or even worse give them a other meaning. IMHO > > > > the scu-api should be stable since day 1 and the ID's should only be > extended. > > > > Marking ID's as deprecated is much better than moving them around. > > > > > > I agree the SCU APIs should be stable since day 1 and the ID should > > > ONLY be extended, but that is the best cases, the reality is, there > > > are different SoCs/Revision, some revisions may remove the resources > > > ID defined in pre-coded SCU firmware, like the > > > IMX_SC_R_DC_0_CAPTURE0 etc., so SCU APIs removes them after real > > > silicon arrived, now latest SCU firmware marks them as UNUSED, they > > > could be replaced by some other new resources in later new SoC, I am > > > NOT sure, but if it happens, this resource ID table should be > > > updated anyway, leaving the out-of-date resource ID table there will have > issues, since it is NOT sync with SCU firmware. > > > > > > So how to resolve such issue? We hope the SCU firmware should be > > > stable since day 1, but the truth is NOT, could be still some > > > updates but NOT very often. And I believe the updates will NOT break old > kernel version. > > Hi Anson, > > Please don't mix the dt-bindings and the kernel related stuff. > Unfortunately the bindings are within the kernel repo which in fact is great for > us kernel developer but the bindings are also used in other projects such as > barebox or other kernels (don't know the BSD guys). So you can't ensure that > your change will break something. Please keep that in mind. > > IMHO solving that issue should be done by the scu firmware. I tought the scu is > a cortex-m4 with a bunch of embedded flash and ram (I don't know that much > about the scu since it is closed/black-boxed). Why do you don't use a > translation table within the scu? As I said earlier I don't like the redefinition of > ID's since they are now part of the dt-bindings. > The bindings can store up to 32bit values which is a large number ;) IMHO > wasting some ID's in favour of stability is a better solution. > As far as I know, those remove resource IDs are pre-defined and has never been used and won't be used anymore by SC firmware. (Anson can double check it) So I think it's safe to remove them or mark them as deprecated. Personally I may prefer to remove them as they never worked to avoid confusing, especially at this early stage for mx8. Regards Dong Aisheng
