Re: [PATCH v4 1/2] dt-bindings: pci: Retrain Link to work around Gen2 training defect.
From: Rob Herring <robh@kernel.org>
Date: 2020-12-11 18:31:51
Also in:
linux-pci, lkml
On Fri, Dec 11, 2020 at 9:03 AM Nadeem Athani [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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. Rob