I had just that question today when reviewing a similar ZTE modem. It appears that its to reset the modem as well: https://github.com/openwrt/openwrt/pull/10418/files#r945125301
Regards, Robert On Sat, 13 Aug 2022 at 19:13, Bjørn Mork <[email protected]> wrote: > > I just got myself a ZTE286D. But after installing OpenWrt I had an > unexpected problem on reboot. The Openwrt DTS includes a gpio-restart > device: > gpio-restart { > compatible = "gpio-restart"; > gpios = <&tlmm 8 GPIO_ACTIVE_HIGH>; > }; > > > The gpio-restart driver is therefore used to reboot the system due to > default priorities. > > I have two concerns about this: > > 1) it's different from OEM, and > 2) it cuts power to the 3.3V VCC console line on reboot > > A quick test indicates that reboot works just fine without using > gpio-restart in OpenWrt too. And a similar node seems to be rare in > this target. AFAICS, this is the only device having one. > > So I wonder if we could/should remove that gpio-restart device. What do > you think? > > The reason I ask is because the VCC toggling causes unnecessary problems > for me. I realize that I have an unusual setup, but I have connected a > bluetooth module to the console port. Toggling the console VCC on > reboot makes it hard/imposible to enter the bootloader, or to capture > the whole boot log. It takes some time before the console server > notices that the bluetooth device disappeared and tries to reconnect. I > believe this is an unwanted side effect. And it wasn't like that with > OEM. > > This is of course only a minor problem. In addition to just pathcing the > DTS myself, I could also put something like > > test -w /sys/bus/platform/drivers/restart-gpio/unbind && echo gpio-restart > >/sys/bus/platform/drivers/restart-gpio/unbind > > into /etc/rc.local. That's a perfectly fine workaround. But I wanted > to ask becasuse of the different behaviour in OEM. > > > Bjørn > > > _______________________________________________ > openwrt-devel mailing list > [email protected] > https://lists.openwrt.org/mailman/listinfo/openwrt-devel _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/mailman/listinfo/openwrt-devel
