[PATCH 1/4] ARM: dts: sun8i: Extend Orange Pi PC dt to also handle the PC Plus

Maxime Ripard maxime.ripard at free-electrons.com
Wed Aug 31 09:28:19 PDT 2016


Hi Hans,

Sorry for the slow response, it was burried in my inbox.

On Sun, Aug 07, 2016 at 04:25:20PM +0200, Hans de Goede wrote:
> Hi,
> 
> On 28-07-16 22:36, Hans de Goede wrote:
> >Hi,
> >
> >On 28-07-16 20:17, Maxime Ripard wrote:
> >>Hi Hans,
> >>
> >>On Tue, Jul 26, 2016 at 11:07:23PM +0200, Hans de Goede wrote:
> >>>>>>Nothing prevents you from including the orange pi pc dts, from the
> >>>>>>orange pi plus dts.
> >>>>>>
> >>>>>>It prevents the duplication you were trying to avoid, and it doesn't
> >>>>>>create all those spurious errors and devices.
> >>>>>
> >>>>>That would solve the copy paste problem on the kernel side, but that
> >>>>>would still mean adding a new u-boot defconfig for this, which means that
> >>>>>all the distro's which ship with prebuild u-boot binaries need to build
> >>>>>for yet another board, something which I would like to avoid.
> >>>>
> >>>>Still, registering devices that are not present on the board is not an
> >>>>option.
> >>>
> >>>Ok, new version send.
> >>>
> >>>What about the other 3 patches in this series ?
> >>
> >>I guess the same comment applies for patch 2.
> >
> >The difference is that there really is no harm at all from
> >enabling the extra usb controllers used on the plus 2e
> >on the plus and plus 2 as well, no errors, no nothing, they
> >just sit their as usb controllers without an usb device plugged
> >in. But if you insist I can do a separate dts + u-boot defconfig
> >for the plus 2e as well (but I would rather not).
> 
> Ping, what is the verdict on this, are you ok with the patch or
> do you want me to create a separate dts file for the Orange Pi
> Plus 2E, note that doing so is going to be highly confusing to
> users, there are 3 plus boards:

I still believe that enabling clocks, regulators, claiming pins for
device that are entirely unused on the board is not ok.

> Orange Pi Plus
> Orange Pi Plus 2   (same as the original plus but with 2G RAM, uses same u-boot defconfig / dts file)

Yes, that makes sense.

> Orange Pi Plus 2E  (drops the USB-hub instead using all 3 host controllers)

However, I'm really worried about this one. If we go this way, there's
essentially no going back. If for some reason we want to have a
separate DT in the future (some unforeseen quirk to apply, pin to
setup that conflicts on another board, etc.), we will be completely
screwed because our users will be expecting to use the common DT,
while it wouldn't be wise anymore.

The other way around is much easier to deal with.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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