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

[Abel Vesa]

On 21-11-23 08:30:17, Alexander Stein wrote:
> 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@xxxxxxx
> > > > > 
> > > > > 
> > > > > ---
> > > > >  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.
> 

I think you're right, the commit b4b844930f27bf7019c should be reverted.

You can send the revert yourself, if you want. If not, let me know.

> Best regards,
> Alexander
> 
>