Cherry-pick "arm64: dts: rockchip: remove vdd_log from rk3399-puma" for 4.14.y?

Cherry-pick "arm64: dts: rockchip: remove vdd_log from rk3399-puma" for 4.14.y?

[Jakob Unterwurzacher]

Dear Greg,

a fix for a voltage instability on our rk3399-puma board went into 4.15 
(commit 87eba0716011, quoted below). As we have users who prefer to stay 
on longterm 4.14, would you consider cherry-picking the commit into 
4.14.y? It applies cleanly and has no effect outside of our rk3399-puma 
board, where it fixes the instability.

Thank you and best regards,
Jakob

> commit 87eba0716011e528f7841026f2cc65683219d0ad
> Author: Klaus Goger <klaus.goger@theobroma-systems.com>
> Date:   Tue Dec 5 08:11:58 2017 +0100
> 
>     arm64: dts: rockchip: remove vdd_log from rk3399-puma
> 
>     vdd_log has no consumer and therefore will not be set to a specific
>     voltage. Still the PWM output pin gets configured and thence the vdd_log
>     output voltage will changed from it's default. Depending on the idle
>     state of the PWM this will slightly over or undervoltage the logic supply
>     of the RK3399 and cause instability with GbE (undervoltage) and PCIe
>     (overvoltage). Since the default value set by a voltage divider is the
>     correct supply voltage and we don't need to change it during runtime we
>     remove the rail from the devicetree completely so the PWM pin will not
>     be configured.
> 
>     Signed-off-by: Klaus Goger <klaus.goger@theobroma-systems.com>
>     Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> 
>  arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi | 11 -----------
>  1 file changed, 11 deletions(-)

Re: Cherry-pick "arm64: dts: rockchip: remove vdd_log from rk3399-puma" for 4.14.y?

[Greg KH]

On Fri, Apr 27, 2018 at 12:13:44PM +0200, Jakob Unterwurzacher wrote:
> Dear Greg,
> 
> a fix for a voltage instability on our rk3399-puma board went into 4.15
> (commit 87eba0716011, quoted below). As we have users who prefer to stay on
> longterm 4.14, would you consider cherry-picking the commit into 4.14.y? It
> applies cleanly and has no effect outside of our rk3399-puma board, where it
> fixes the instability.

Sure, now queued up, thanks.

greg k-h