On 08/03/18 11:00, Jacob Chen wrote: > Hi Hans, > > 2018-02-07 20:00 GMT+08:00 Hans Verkuil <hverkuil@xxxxxxxxx>: >> On 12/29/17 08:52, Shunqian Zheng wrote: >>> From: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx> >>> >>> Add the header for userspace >> >> General note: I saw four cases where this documentation referred to the >> datasheet. Three comments on that: >> >> 1) You don't say which datasheet. >> 2) I assume the datasheet is under NDA? > > This datasheet can't be got by customers, even under NDA. OK. This should be mentioned somewhere. > >> 3) You do need to give enough information so a reasonable default can be >> used. I mentioned in an earlier review that creating an initial params >> struct that can be used as a templete would be helpful (or even >> required), and that would be a good place to put such defaults. >> > > It don't need a default config > For applcation writers, they can just init it with zero data, and only > set value for the part they concerned. This too should be clearly documented. This is very useful information for users of this API. > > As for ABI, i have checked there is no mismatches. > Those structures is 32 bit aligned both in 64bit/32bit env, since > there is no 64bit value. > "__attribute__ ((packed))" can avoid mismatches happen when we add a > 64bit value to those structures. > > As robin said, enums and bools are not guaranteed to be consistent > between different compiler, so it's a potential risk. > I have replace bools with unsigned char and enums with unsigned int. Excellent. Regards, Hans -- 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
