* qianfan <qianfanguijin@xxxxxxx> [220216 04:05]: > 在 2022/2/14 15:50, Tony Lindgren 写道: > > Well seems like the boottime of 1.25 seconds to having the gpio probed should > > be way longer than your bootloader configured watchdog timeout :) What do you > > have the bootloader set the watchdog timeout? > I had sniffer the gpio data by using logic analysis, when the linux gpio-wdt > driver toggle watchdog pin, it passed about 5 seconds after the u-boot done. > And the gpio watchdog's deadline is 1.6s. Well on my beaglebone black looks like gpios are initialized around 1.7s, but pinctrl is initialized around 0.25s. You could create some driver that in it's init sets the related gpio pin to PIN_OUTPUT_PULLUP | SAFE_MODE to kick the gpio watchdog, and then exits releasing the pinmux so the gpio based driver can take over. Or maybe your gpio watchdog driver could do pin configuration in init, then do what it currently does in probe. Of course booting things faster would be the best solution, but that can easily get delayed with kernel updates with deferred probe for example. Regards, Tony
