Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx> writes: > 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 > A grep of the `pwm2` shows that there's such block in rk3399-nanopi4.dtsi: &pwm2 { pinctrl-names = "active"; pinctrl-0 = <&pwm2_pin_pull_down>; status = "okay"; }; But last time I checked, using the mainline U-Boot (the roc-rk3399-pc is in mainline now) with mainline linux v5.2-rc7, no such setting is necessary, and the board boots happily. I cannot find the use of "active" pinctrl state in the `drivers/pwm/pwm-rockchip.c`. If the pinctrl state needs to be setup as default, the `pinctrl-names` needs to be "default" or "init" (see `drivers/base/pinctrl.c`) . Jagan, what version of board do you use? I checked with "ROC-RK3399-PC-V1.0-A 2018-07-12". Thanks -- Levin Du
