Messages in this thread | | | Subject | Re: [PATCH v4 1/2] dt-bindings: pci: Retrain Link to work around Gen2 training defect. | From | Kishon Vijay Abraham I <> | Date | Mon, 14 Dec 2020 09:50:56 +0530 |
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Hi Nadeem,
On 12/12/20 12:37 pm, Athani Nadeem Ladkhan wrote: > Hi Rob / Kishon, > >> -----Original Message----- >> From: Rob Herring <robh@kernel.org> >> Sent: Friday, December 11, 2020 10:32 PM >> To: Athani Nadeem Ladkhan <nadeem@cadence.com> >> Cc: Tom Joseph <tjoseph@cadence.com>; Lorenzo Pieralisi >> <lorenzo.pieralisi@arm.com>; Bjorn Helgaas <bhelgaas@google.com>; PCI >> <linux-pci@vger.kernel.org>; linux-kernel@vger.kernel.org; Kishon Vijay >> Abraham I <kishon@ti.com>; devicetree@vger.kernel.org; Milind Parab >> <mparab@cadence.com>; Swapnil Kashinath Jakhade >> <sjakhade@cadence.com>; Parshuram Raju Thombare >> <pthombar@cadence.com> >> 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@cadence.com> >> 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@cadence.com> >>> --- >>> 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.
Thank You, Kishon
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