[PATCH] arm64: dts: rockchip: Fix iomux for PCIe on rk3399

[Heiko Stübner]

Am Freitag, 4. Dezember 2020, 13:33:16 CET schrieb Vicente Bergas:
> On Fri, Dec 4, 2020 at 1:01 PM Robin Murphy <robin.murphy at arm.com> wrote:
> >
> > On 2020-12-01 15:05, Vicente Bergas wrote:
> > > Fix PCIe pins according to the documentation
> > > http://opensource.rock-chips.com/images/e/ee/Rockchip_RK3399TRM_V1.4_Part1-20170408.pdf
> > > in page 301:
> > > GRF_GPIO2D_IOMUX[5:4] gpio2d2_sel
> > >    0: gpio
> > >    1: sdio_detectn
> > >    2: pcie_clkreqn
> > > and page 313:
> > > GRF_GPIO4D_IOMUX[1:0] gpio4d0_sel
> > >    0: gpio
> > >    1: pcie_clkreqnb
> >
> > What exactly is this fixing? Commit 461a00bb9d53 explicitly removed pin
> > configurations for these functions on the grounds that they apparently
> > don't work. FWIW it looks like they might also be related to some magic
> > in GRF_SOC_CON7 which nobody's touching either.
> >
> > Robin.
> 
> This fixes nothing.
> I've got a non-working NVMe and while debugging the issue found this
> mismatch between the DTS and documentation.
> So i fixed it by changing the DTS.
> Regarding 461a00bb9d53 it looks like the issue is in the documentation
> instead, but there are no (public) errata documents.
> The issue with the NVMe i've got was unrelated: controller chip not
> correctly soldered.
> Now i've tested that NVMe again without this change and it still
> works, so, ignore this patch.
> Thanks for reviewing.

thanks for letting us know ;-) 

And also thanks Robin for digging up the history of this.
I was about to ask something similar but hadn't found the time yet
to dig through past pcie changes.


Heiko