[U-Boot] dm: pinctrl: Prevent (re-)configuring pins when already done before relocation

Alex Kiernan
2019-01-08T23:13:09Z

On Tue, Jan 8, 2019 at 10:52 PM Lukasz Majewski <lukma@denx.de> wrote:
>
> Hi Alex,
>
> > On Thu, Dec 27, 2018 at 3:49 PM Tom Rini <trini@konsulko.com> wrote:
> > >
> > > On Tue, Dec 18, 2018 at 12:30:50PM +0100, Lukasz Majewski wrote:
> > >
> > > > This commit prevents from re-configuring pins if those were
> > > > configured before relocation.
> > > >
> > > > Some pins - like UART or DDR must be setup before relocation
> > > > (as they have 'u-boot,dm-pre-reloc' property set in DTS). Without
> > > > this change, those pins are re-configured after relocation
> > > > (pre_reloc_only = 0, so we do not "continue").
> > > > Such behavior may be a problem for DDR PAD configuration, as they
> > > > might be already leveled/tuned with original setup).
> > > >
> > > > Signed-off-by: Lukasz Majewski <lukma@denx.de>
> > >
> > > Applied to u-boot/master, thanks!
> > >
> >
> > I've bisected out to this commit and it's slightly broken things for
> > me on an AM3352. It all works fine so long as I boot MLO from MMC (so
> > the MMC is probed, pinctrl setup), but if I boot from UART then I get
> > to full U-Boot, MMC hasn't been probed and the pinmuxing isn't set up
> > for the MMC.
>
> I suppose that the pinmux node have set "u-boot,dm-pre-reloc"
> property?
>

Yeah, well "u-boot,dm-spl", though now I re-read the docs I guess
that's equivalent to "u-boot,dm-pre-reloc" as I've no TPL.

> The problem is not with lack of eMMC probing - it is with pinctrl nodes
> having "u-boot,dm-pre-reloc" set in DTS and the eMMC is probed after
> MLO/SPL.
> It looks like your use case implicitly depends on pinmux being
> reconfigured no matter if we are pre-relocated (MLO) or afterwards.
>

Yes, that's a much clearer description...

--
Alex Kiernan