MIPS: SEAD-3: Set interrupt-parent per-device, not at root node

The SEAD-3 board may be configured with or without a MIPS Global
Interrupt Controller (GIC). Because of this we have a device tree with a
default case of a GIC present, and code to fixup the device tree based
upon a configuration register that indicates the presence of the GIC.

In order to keep this DT fixup code simple, the interrupt-parent
property was specified at the root node of the SEAD-3 DT, allowing the
fixup code to simply change this property to the phandle of the CPU
interrupt controller if a GIC is not present & affect all
interrupt-using devices at once. This however causes a problem if we do
have a GIC & the device tree is used as-is, because the interrupt-parent
property of the root node applies to the CPU interrupt controller node.
This causes a cycle when of_irq_init() attempts to probe interrupt
controllers in order and boots fail due to a lack of configured
interrupts, with this message printed on the kernel console:

[    0.000000] OF: of_irq_init: children remain, but no parents

Fix this by removing the interrupt-parent property from the DT root node
& instead setting it for each device which uses interrupts, ensuring
that the CPU interrupt controller node has no interrupt-parent &
allowing of_irq_init() to identify it as the root interrupt controller.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reported-by: Keng Koh <keng.koh@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16187/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/boot/dts/mti/sead3.dts b/arch/mips/boot/dts/mti/sead3.dts
index f327791cbcb5c0c9e9dc0cba350fed509fc6aa70..cabe256f9a68419813c6adef5be1df584302974c 100644 (file)
--- a/arch/mips/boot/dts/mti/sead3.dts
+++ b/arch/mips/boot/dts/mti/sead3.dts
@@ -11,7 +11,6 @@
        #size-cells = <1>;
        compatible = "mti,sead-3";
        model = "MIPS SEAD-3";
-       interrupt-parent = <&gic>;
 
        chosen {
                stdout-path = "serial1:115200";
@@ -60,6 +59,7 @@
                compatible = "generic-ehci";
                reg = <0x1b200000 0x1000>;
 
+               interrupt-parent = <&gic>;
                interrupts = <0>; /* GIC 0 or CPU 6 */
 
                has-transaction-translator;
@@ -222,6 +222,7 @@
 
                clock-frequency = <14745600>;
 
+               interrupt-parent = <&gic>;
                interrupts = <3>; /* GIC 3 or CPU 4 */
 
                no-loopback-test;
@@ -236,6 +237,7 @@
 
                clock-frequency = <14745600>;
 
+               interrupt-parent = <&gic>;
                interrupts = <2>; /* GIC 2 or CPU 4 */
 
                no-loopback-test;
@@ -246,6 +248,7 @@
                reg = <0x1f010000 0x10000>;
                reg-io-width = <4>;
 
+               interrupt-parent = <&gic>;
                interrupts = <0>; /* GIC 0 or CPU 6 */
 
                phy-mode = "mii";

diff --git a/arch/mips/generic/board-sead3.c b/arch/mips/generic/board-sead3.c
index 39e11bd249cf87fed061c06a19749a6ce92ba983..f109a6b9fdd0806774da38c6abecdf1d91e7de27 100644 (file)
--- a/arch/mips/generic/board-sead3.c
+++ b/arch/mips/generic/board-sead3.c
@@ -87,14 +87,16 @@ static __init int remove_gic(void *fdt)
                return -EINVAL;
        }
 
-       err = fdt_setprop_u32(fdt, 0, "interrupt-parent", cpu_phandle);
-       if (err) {
-               pr_err("unable to set root interrupt-parent: %d\n", err);
-               return err;
-       }
-
        uart_off = fdt_node_offset_by_compatible(fdt, -1, "ns16550a");
        while (uart_off >= 0) {
+               err = fdt_setprop_u32(fdt, uart_off, "interrupt-parent",
+                                     cpu_phandle);
+               if (err) {
+                       pr_warn("unable to set UART interrupt-parent: %d\n",
+                               err);
+                       return err;
+               }
+
                err = fdt_setprop_u32(fdt, uart_off, "interrupts",
                                      cpu_uart_int);
                if (err) {
@@ -117,6 +119,12 @@ static __init int remove_gic(void *fdt)
                return eth_off;
        }
 
+       err = fdt_setprop_u32(fdt, eth_off, "interrupt-parent", cpu_phandle);
+       if (err) {
+               pr_err("unable to set ethernet interrupt-parent: %d\n", err);
+               return err;
+       }
+
        err = fdt_setprop_u32(fdt, eth_off, "interrupts", cpu_eth_int);
        if (err) {
                pr_err("unable to set ethernet interrupts property: %d\n", err);
@@ -129,6 +137,12 @@ static __init int remove_gic(void *fdt)
                return ehci_off;
        }
 
+       err = fdt_setprop_u32(fdt, ehci_off, "interrupt-parent", cpu_phandle);
+       if (err) {
+               pr_err("unable to set EHCI interrupt-parent: %d\n", err);
+               return err;
+       }
+
        err = fdt_setprop_u32(fdt, ehci_off, "interrupts", cpu_ehci_int);
        if (err) {
                pr_err("unable to set EHCI interrupts property: %d\n", err);