Messages in this thread | | | Date | Tue, 1 Dec 2015 12:23:51 -0800 | From | Joshua Clayton <> | Subject | Re: [PATCH 6/9] rtc-pcf2123: avoid resetting the clock if possible |
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On Wed, 25 Nov 2015 00:25:12 +0100 Alexandre Belloni <alexandre.belloni@free-electrons.com> wrote:
> On 04/11/2015 at 07:36:37 -0800, Joshua Clayton wrote : > > + ret = pcf2123_rtc_read_time(dev, &tm); > > + if (ret < 0) > > + return false; > > + > > + if (rtc_valid_tm(&tm) < 0) { > > + dev_err(dev, "retrieved date/time is not > > valid.\n"); > > + return false; > > + } > > + > > I would remove that test as basically, the date/time will only be > valid when OSC_HAS_STOPPED is not set. > OSC_HAS_STOPPED really only protects us in case everything else looks good, but we've lost power. There are other reasons to check for a valid time. Specifically, if there is no communication with the device, the spi operation will succeed and return all zeros or all ones. Since either of these results in an invalid time, it is a nice way to probe whether we really have a pcf2123 compatible device.
I don't think I should remove this test, but I can add a comment
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