Hello Guenter, On Fri, Feb 08, 2019 at 06:05:43AM -0800, Guenter Roeck wrote: > On 2/8/19 2:52 AM, Uwe Kleine-König wrote: > > Hello, > > > > it's unclear to me, which bits I am supposed to set in the bootstatus > > member of struct watchdog_device at probe time. > > > > The i.MX watchdog differentiates the following reset causes: > > > > - Power On > None. > > > - external reset > > None. > > > - watchdog timeout > > WDIOF_CARDRESET > > > - software reset using a bit in the watchdog register set > > > > (Not all i.MX variants implement all bits according to the respective > > reference manuals.) > > > > Should "Power On" result in setting WDIOF_POWERUNDER? > > > No. > > > Should "software reset [...]" result in WDIOF_CARDRESET? > > > That would be the best fit if you want a bit to be set, but it would be > misleading since it would suggest that the watchdog fired. > > > Should "external reset" result in WDIOF_EXTERN1? (I guess that no) > > No. In a custom kernel patch stack I found a patch that uses (apart from WDIOF_CARDRESET also) WDIOF_POWERUNDER and WDIOF_EXTERN1 to differentiate the different reset causes. Now that you told using this is wrong, I wonder how these are supposed to be used instead; and there are a few more that according to Documentation/watchdog/watchdog-kernel-api.txt might be used to set bootstatus. Are these a relic? What do these signal? IMHO there is a patch opportunity waiting to improve the documenation :-) Or maybe even change watchdog_get_status() to ensure that only WDIOF_CARDRESET, WDIOF_MAGICCLOSE and WDIOF_KEEPALIVEPING can be set? Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |
