On Wed, Sep 01, 2021 at 12:15:23PM +0100, Peter Robinson wrote: > On Wed, 2021-08-18 at 07:53 -0700, Guenter Roeck wrote: > > On 8/18/21 7:49 AM, Hans de Goede wrote: > > > Hi, > > > > > > On 8/18/21 4:13 PM, Guenter Roeck wrote: > > > > On 8/18/21 2:57 AM, Jose Noguera wrote: > > > > > Hello all! > > > > > > > > > > I’m Jose, working in Red Hat on Fedora IoT and RHEL For Edge > > > > > related projects. > > > > > > > > > > While trying to add the feature of figuring out whether the > > > > > current boot was triggered or not by a hardware watchdog using > > > > > wdctl, we’ve found an odd behaviour in the drivers definition > > > > > that we would like to check with you. > > > > > > > > > > Looking specifically for the flag WDIOF_CARDRESET, we can find > > > > > 40 files that contain it: > > > > > > > > > > $ grep -rl CARDRESET drivers/watchdog/ | wc -l > > > > > 40 > > > > > > > > > > but only 19 of them have the flag advertised in the options > > > > > field of the watchdog_info struct returned by the > > > > > WDIOC_GETSUPPORT ioctl. > > > > > > > > > > This leads to wdctl not showing WDIOF_CARDRESET for drivers > > > > > like i6300esb, even when the board had been reset this way: > > > > > > > > > > $ sudo wdctl > > > > > Device: /dev/watchdog0 > > > > > Identity: i6300ESB timer [version 0] > > > > > Timeout: 30 seconds > > > > > Pre-timeout: 0 seconds > > > > > > > > > > FLAG DESCRIPTION STATUS BOOT-STATUS > > > > > KEEPALIVEPING Keep alive ping reply 1 0 > > > > > MAGICCLOSE Supports magic close char 0 0 > > > > > SETTIMEOUT Set timeout (in seconds) 0 0 > > > > > > > > > > Working with Hans (in CC), we added a little patch (BugZilla > > > > > ticket: 1993983) on wdctl and this would be the output of the > > > > > command when it was a card reset triggered boot: > > > > > > > > > > $ sudo wdctl > > > > > Device: /dev/watchdog0 > > > > > Identity: i6300ESB timer [version 0] > > > > > Thank you all for your time, > > > > > > > > > > Jose > > > > > > > > > Timeout: 30 seconds > > > > > Pre-timeout: 0 seconds > > > > > > > > > > FLAG DESCRIPTION STATUS BOOT-STATUS > > > > > CARDRESET Card previously reset the CPU 1 1 > > > > > KEEPALIVEPING Keep alive ping reply 1 0 > > > > > MAGICCLOSE Supports magic close char 0 0 > > > > > SETTIMEOUT Set timeout (in seconds) 0 0 > > > > > > > > > > So our question is, may we know what is intended to be present > > > > > in ident.options? What should the API call WDIOC_GETSUPPORT > > > > > return in the options field? > > > > > > > > > > > > > Search for WDIOC_GETSUPPORT in Documentation/watchdog/watchdog- > > > > api.rst. > > > > I don't see any ambiguity there. Patches welcome. > > > > > > Ok, so drivers which may set CARDRESET in their GETBOOTSTATUS > > > reply, but > > > don't advertise this in their GETSUPPORT watchdog_info.options > > > reply > > > are buggy and should be fixed, got it. Thanks. > > > > > > I've made a note about fixing this in a possible-kernel-projects > > > document > > > which I keep for when people who are interested in kernel > > > development > > > ask me for projects. > > > > > > > With an add-on: If the driver in question is an old-style driver, > > anyone > > affected by the problem should really convert the driver to support > > the watchdog subsystem. > > Would you have a link to any docs/posts outlining what needs to be done > for conversion to the watchdog subsystem? Documentation/watchdog/convert_drivers_to_kernel_api.rst should help. Guenter
