Hi Heiko, On Mon, Sep 30, 2019 at 2:51 AM Heiko Stuebner <heiko@xxxxxxxxx> wrote: > > Hi Jagan, > > Am Donnerstag, 19. September 2019, 07:28:17 CEST schrieb Jagan Teki: > > ROC-PC is not able to boot linux console if PWM2_d is > > unattached to any pinctrl logic. > > > > To be precise the linux boot hang with last logs as, > > ... > > ..... > > [ 0.003367] Console: colour dummy device 80x25 > > [ 0.003788] printk: console [tty0] enabled > > [ 0.004178] printk: bootconsole [uart8250] disabled > > > > In ROC-PC the PWM2_d pin is connected to LOG_DVS_PWM of > > VDD_LOG. So, for normal working operations this needs to > > active and pull-down. > > > > This patch fix, by attaching pinctrl active and pull-down > > the pwm2. > > This looks highly dubious on first glance. The pwm subsystem nor > the Rockchip pwm driver do not do any pinctrl handling. > > So I don't really see where that "active" pinctrl state is supposed > to come from. > > Comparing with the pwm driver in the vendor tree I see that there > is such a state defined there. But that code there also looks strange > as that driver never again leaves this active state after entering it. > > Also for example all the Gru devices run with quite a number of pwm- > regulators without needing additional fiddling with the pwm itself, so > I don't really see why that should be different here. I deed, I was supposed to think the same. but the vendor kernel dts from firefly do follow the pwm2 pinctrl [1]. I wouldn't find any information other than this vensor information, ie one of the reason I have marked "Levin Du" who initially supported this board. One, think I have seen was this pinctrl active fixed the boot hang. any inputs from would be very helpful. Levin Du, any inputs? [1] https://github.com/FireflyTeam/kernel/blob/stable-4.4-rk3399-linux/arch/arm64/boot/dts/rockchip/rk3399-roc-pc.dtsi#L1184
