Hi, On 24/09/2020 07:23:18+0000, Qiang Zhao wrote: > > > Yes, you are right, There is not a fundamental solution. > > > However it somewhat avoid this situation at least. > > > > > > And if without this issue, > > > is it correct to register a rtc device as watchdog no matter it is used as > > watchdog on the board? > > > Every time Linux are booted up, watchdog device should be configured to the > > right one manually. > > > So the patch are useful, even though it is not for the issue. > > > > > > What should we do to really resolve this issue? > > > > I still think we need a kernel solution here. I would expect that most assembled > > pcf2127 chips are unable to act as a watchdog (i.e. don't have the RST output > > connected to something that resets the machine). > > > > So my favoured solution would be a positive property like: > > > > has-watchdog; > > > > or something similar. In my eyes this is definitely something we want to specify > > in the device tree because it is a relevant hardware property. > > I consider it a bug to give a watchdog device to userspace that isn't functional. > > > > Best regards > > Uwe > > I strongly agree with you! It should be positive property. > However, we couldn't identify which board are using pcf2127 as watchdog, > So we are unable to modify the boards' dts to correct (watchdog or not) in this patchset. > > I noticed that only LS series platforms and imx6 have pcf2127 node, as far as I know, the LS platforms don't use it as watchdog, > But I am not sure about imx6 > I don't think there is any user upstream and it is recent engouh that we can probably make that a positive property. Bruno, is it ok for you? you are the only know user of the feature. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
