Hi Andrew, Am 27.08.2017 um 15:47 schrieb Andrew Lunn: >> Thanks. Did you read the RFC question in the cover letter as well and >> have any comments? Downstream has an rtc-base-year = <2014>; property >> that I had left out in this RFC and due to your ack not included in v2. >> >> Should we default to 2014 in the driver and add an optional base-year >> property once we encounter a diverging device, or should we make it >> required from the beginning? I did not spot any other rtc binding with >> such a property and would appreciate a clarification. > > From the perspective of the hardware, does it care what the base is? The hardware stores a 15-bit number of days since Jan 1st of that base year. It does not store the base year. The datasheet does not name such a base year. No manual is available. The driver needs to get it from somewhere for calculating day/month/year in read_time and days in set_time. The read_offset/set_offset API appeared to be something different. > A device using a different base will initially return the wrong > time. But once the correct time has been written back, it will be O.K. > > This only becomes an issue if a device is used with different OSs, > which have different bases. Swapping back and forth between OSs then > becomes an issue. These are TV boxes, so yes, I'm dual-booting into Android with a vendor 4.1 kernel and would like to keep date compatibility. https://en.opensuse.org/HCL:Zidoo_X9S https://en.opensuse.org/HCL:ProBox2_Ava https://en.opensuse.org/HCL:Lake1 As stated in the v2 rtc commit message, 2014 is the base year encountered on all three devices that I've had access to. @Jiang, if you're using a different base year, please speak up! > KISS suggests not having a base in DT until it is actually > required. Since it is an additional property, it does not break > backwards compatibility when added. That's what I've attempted here - but for RDA8810PL serial Rob said he did not want future changes to my binding, therefore I am asking for his confirmation here. Regards, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) -- 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
