Hi, On 14/12/20 8:35 pm, Rob Herring wrote: > On Sun, Dec 13, 2020 at 10:21 PM Kishon Vijay Abraham I <kishon@xxxxxx> wrote: >> >> Hi Nadeem, >> >> On 12/12/20 12:37 pm, Athani Nadeem Ladkhan wrote: >>> Hi Rob / Kishon, >>> >>>> -----Original Message----- >>>> From: Rob Herring <robh@xxxxxxxxxx> >>>> Sent: Friday, December 11, 2020 10:32 PM >>>> To: Athani Nadeem Ladkhan <nadeem@xxxxxxxxxxx> >>>> Cc: Tom Joseph <tjoseph@xxxxxxxxxxx>; Lorenzo Pieralisi >>>> <lorenzo.pieralisi@xxxxxxx>; Bjorn Helgaas <bhelgaas@xxxxxxxxxx>; PCI >>>> <linux-pci@xxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; Kishon Vijay >>>> Abraham I <kishon@xxxxxx>; devicetree@xxxxxxxxxxxxxxx; Milind Parab >>>> <mparab@xxxxxxxxxxx>; Swapnil Kashinath Jakhade >>>> <sjakhade@xxxxxxxxxxx>; Parshuram Raju Thombare >>>> <pthombar@xxxxxxxxxxx> >>>> Subject: Re: [PATCH v4 1/2] dt-bindings: pci: Retrain Link to work around >>>> Gen2 training defect. >>>> >>>> EXTERNAL MAIL >>>> >>>> >>>> On Fri, Dec 11, 2020 at 9:03 AM Nadeem Athani <nadeem@xxxxxxxxxxx> >>>> wrote: >>>>> >>>>> Cadence controller will not initiate autonomous speed change if >>>>> strapped as Gen2. The Retrain Link bit is set as quirk to enable this speed >>>> change. >>>>> Adding a quirk flag based on a new compatible string. >>>>> >>>>> Signed-off-by: Nadeem Athani <nadeem@xxxxxxxxxxx> >>>>> --- >>>>> Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml | 4 >>>>> +++- >>>>> 1 file changed, 3 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git >>>>> a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >>>>> b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >>>>> index 293b8ec318bc..204d78f9efe3 100644 >>>>> --- a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >>>>> +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.yaml >>>>> @@ -15,7 +15,9 @@ allOf: >>>>> >>>>> properties: >>>>> compatible: >>>>> - const: cdns,cdns-pcie-host >>>>> + enum: >>>>> + - cdns,cdns-pcie-host >>>>> + - cdns,cdns-pcie-host-quirk-retrain >>>> >>>> So, we'll just keep adding quirk strings on to the compatible? I don't think so. >>>> Compatible strings should map to a specific implementation/platform and >>>> quirks can then be implied from them. This is the only way we can implement >>>> quirks in the OS without firmware >>>> (DT) changes. >>> Ok, I will change the compatible string to " ti,j721e-pcie-host" in place of " cdns,cdns-pcie-host-quirk-retrain" . >>> @Kishon Vijay Abraham I: Is this fine? Or will you suggest an appropriate name? >> >> IMHO it should be something like "cdns,cdns-pcie-host-vX", since the >> quirk itself is not specific to TI platform rather Cadence IP version. > > That's fine if Cadence has a need for it, but for TI platforms use the > TI compatible string. ECOs on version X IP without changing X is not > uncommon. Okay. I re-worked the patch to be applicable only to TI's J721E SoC http://lore.kernel.org/r/20201215070009.27937-1-kishon@xxxxxx Thank You, Kishon
