On Thu, Aug 18, 2022 at 12:46:33PM +0300, Krzysztof Kozlowski wrote: > On 18/08/2022 12:22, Shawn Guo wrote: > > On Thu, Aug 18, 2022 at 10:51:02AM +0300, Krzysztof Kozlowski wrote: > >> On 18/08/2022 04:33, Shawn Guo wrote: > >>> On Mon, Jul 04, 2022 at 11:12:09AM +0200, Krzysztof Kozlowski wrote: > >>>>> diff --git a/Documentation/devicetree/bindings/net/fsl,fec.yaml b/Documentation/devicetree/bindings/net/fsl,fec.yaml > >>>>> index daa2f79a294f..6642c246951b 100644 > >>>>> --- a/Documentation/devicetree/bindings/net/fsl,fec.yaml > >>>>> +++ b/Documentation/devicetree/bindings/net/fsl,fec.yaml > >>>>> @@ -40,6 +40,10 @@ properties: > >>>>> - enum: > >>>>> - fsl,imx7d-fec > >>>>> - const: fsl,imx6sx-fec > >>>>> + - items: > >>>>> + - enum: > >>>>> + - fsl,imx8ulp-fec > >>>>> + - const: fsl,imx6ul-fec > >>>> > >>>> This is wrong. fsl,imx6ul-fec has to be followed by fsl,imx6q-fec. I > >>>> think someone made similar mistakes earlier so this is a mess. > >>> > >>> Hmm, not sure I follow this. Supposing we want to have the following > >>> compatible for i.MX8ULP FEC, why do we have to have "fsl,imx6q-fec" > >>> here? > >>> > >>> fec: ethernet@29950000 { > >>> compatible = "fsl,imx8ulp-fec", "fsl,imx6ul-fec"; > >>> ... > >>> }; > >> > >> Because a bit earlier this bindings is saying that fsl,imx6ul-fec must > >> be followed by fsl,imx6q-fec. > > > > The FEC driver OF match table suggests that fsl,imx6ul-fec and fsl,imx6q-fec > > are not really compatible. > > > > static const struct of_device_id fec_dt_ids[] = { > > { .compatible = "fsl,imx25-fec", .data = &fec_devtype[IMX25_FEC], }, > > { .compatible = "fsl,imx27-fec", .data = &fec_devtype[IMX27_FEC], }, > > { .compatible = "fsl,imx28-fec", .data = &fec_devtype[IMX28_FEC], }, > > { .compatible = "fsl,imx6q-fec", .data = &fec_devtype[IMX6Q_FEC], }, > > { .compatible = "fsl,mvf600-fec", .data = &fec_devtype[MVF600_FEC], }, > > { .compatible = "fsl,imx6sx-fec", .data = &fec_devtype[IMX6SX_FEC], }, > > { .compatible = "fsl,imx6ul-fec", .data = &fec_devtype[IMX6UL_FEC], }, > > I don't see here any incompatibility. Binding driver with different > driver data is not a proof of incompatible devices. To me, different driver data is a good sign of incompatibility. It mostly means that software needs to program the hardware block differently. > Additionally, the > binding describes the hardware, not the driver. > > > { .compatible = "fsl,imx8mq-fec", .data = &fec_devtype[IMX8MQ_FEC], }, > > { .compatible = "fsl,imx8qm-fec", .data = &fec_devtype[IMX8QM_FEC], }, > > { /* sentinel */ } > > }; > > MODULE_DEVICE_TABLE(of, fec_dt_ids); > > > > Should we fix the binding doc? > > Maybe, I don't know. The binding describes the hardware, so based on it > the devices are compatible. Changing this, except ABI impact, would be > possible with proper reason, but not based on Linux driver code. Well, if Linux driver code is written in the way that hardware requires, I guess that's just based on hardware characteristics. To me, having a device compatible to two devices that require different programming model is unnecessary and confusing. Shawn