RE: [PATCH 4/4] dt-bindings: pci: layerscape-pci: define aer/pme interrupts

-----Original Message-----
From: Rob Herring <robh@kernel.org>
Sent: Monday, November 29, 2021 8:02 PM
To: Leo Li <redacted>
Cc: Bjorn Helgaas <bhelgaas@google.com>; linux-pci@vger.kernel.org;
devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; Z.Q. Hou
[off-list ref]
Subject: Re: [PATCH 4/4] dt-bindings: pci: layerscape-pci: define aer/pme
interrupts

On Fri, Nov 19, 2021 at 06:16:21PM -0600, Li Yang wrote:

quoted

Some platforms using this controller have separated interrupt lines
for aer or pme events instead of having a single interrupt line for
miscellaneous events.  Define interrupts in the binding for these
interrupt lines.

Signed-off-by: Li Yang <redacted>
---
 .../devicetree/bindings/pci/layerscape-pci.txt     | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/layerscape-pci.txt

b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
index 8fd6039a826b..bcf11bfc4bab 100644

--- a/Documentation/devicetree/bindings/pci/layerscape-pci.txt
+++ b/Documentation/devicetree/bindings/pci/layerscape-pci.txt

@@ -31,8 +31,13 @@ Required properties:
 - reg: base addresses and lengths of the PCIe controller register blocks.
 - interrupts: A list of interrupt outputs of the controller. Must contain an
   entry for each entry in the interrupt-names property.
-- interrupt-names: Must include the following entries:
-  "intr": The interrupt that is asserted for controller interrupts
+- interrupt-names: It could include the following entries:
+  "aer": For interrupt line reporting aer events when non MSI/MSI-X/INTx

mode

quoted

+		is used
+  "pme": For interrupt line reporting pme events when non MSI/MSI-

X/INTx mode

quoted

+		is used
+  "intr": For interrupt line reporting miscellaneous controller
+events
+  ......
 - fsl,pcie-scfg: Must include two entries.
   The first entry must be a link to the SCFG device node
   The second entry is the physical PCIe controller index starting from '0'.

@@ -52,8 +57,9 @@ Example:
 		reg = <0x00 0x03400000 0x0 0x00010000   /* controller

registers */

quoted

 		       0x40 0x00000000 0x0 0x00002000>; /* configuration space

*/

quoted

 		reg-names = "regs", "config";
-		interrupts = <GIC_SPI 177 IRQ_TYPE_LEVEL_HIGH>; /*

controller interrupt */

quoted

-		interrupt-names = "intr";
+		interrupts = <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>, /* aer

interrupt */

quoted

+			<GIC_SPI 177 IRQ_TYPE_LEVEL_HIGH>; /* pme

interrupt */

quoted

+		interrupt-names = "aer", "pme";

This isn't a compatible change. The h/w suddenly has no 'intr'
interrupt?

The original 'intr' was just a place holder for a HW interrupt signal without a clear definition of events associated.  Some later SoC has more interrupt signals to associate with more specific events.

If needed, we can keep the "intr" interrupt-name there just for backward compatibility although it was never used in Linux.

quoted

 		fsl,pcie-scfg = <&scfg 0>;
 		#address-cells = <3>;
 		#size-cells = <2>;
--
2.25.1