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? Nadeem > > Rob
