(EXT) Re: (EXT) Re: [PATCH v4 12/12] dt-bindings: serial: fsl-lpuart: Add i.MX8DXL compatible

[Alexander Stein]

Am Montag, dem 22.11.2021 um 18:45 +0200 schrieb Abel Vesa:
> On 21-11-19 08:17:11, Alexander Stein wrote:
> > Am Donnerstag, dem 18.11.2021 um 19:04 -0600 schrieb Rob Herring:
> > > On Wed, Nov 10, 2021 at 07:46:55PM +0200, Abel Vesa wrote:
> > > > Add i.MX8DXL lpuart compatible to the bindings documentation.
> > > > 
> > > > Signed-off-by: Abel Vesa <
> > > > abel.vesa at nxp.com
> > > > 
> > > > 
> > > > ---
> > > >  Documentation/devicetree/bindings/serial/fsl-lpuart.yaml | 4
> > > > ++++
> > > >  1 file changed, 4 insertions(+)
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/serial/fsl-
> > > > lpuart.yaml b/Documentation/devicetree/bindings/serial/fsl-
> > > > lpuart.yaml
> > > > index dc1f0e07cbd4..fa8a602ccb22 100644
> > > > --- a/Documentation/devicetree/bindings/serial/fsl-lpuart.yaml
> > > > +++ b/Documentation/devicetree/bindings/serial/fsl-lpuart.yaml
> > > > @@ -27,6 +27,10 @@ properties:
> > > >        - items:
> > > >            - const: fsl,imx8qm-lpuart
> > > >            - const: fsl,imx8qxp-lpuart
> > > > +      - items:
> > > > +          - const: fsl,imx8dxl-lpuart
> > > > +          - const: fsl,imx8qxp-lpuart
> > > > +          - const: fsl,imx7ulp-lpuart
> > > 
> > > I'm confused why 8dxl is compatible with 7ulp, but 8qm is not?
> > > From
> > > the 
> > > driver, it looks like the difference is clocks.
> > 
> > There is a difference between 8qm and 7ulp regarding the clocks.
> > Are
> > they still considered compatible? Depending on the answer [1] might
> > not
> > be the correct solution for earlycon regression on 8qm.
> > 
> 
> In NXP's tree, they are not compatible.
> 
> See here:
> 
> https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8qm-ss-dma.dtsi?h=lf-5.10.y#n9

Well, commit 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b4b844930f27bf7019c0bbd8cc575dde32e00ecc
 says otherwise.
This might be true for earlycon only, because clocks should be setup
already.

Together with your other mail regarding the imx7ulp fixup,
commit b4b844930f27bf7019c0bbd8cc575dde32e00ecc should just be reverted
in order to get earlycon running again on imx8qm and imx8qxp, IMHO.

Best regards,
Alexander