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. Rob
