From: Paul Burton paul.burton@imgtec.com
[ Upstream commit fbdc674ba33c3791b315a546019e570e3e94e599 ]
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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- arch/mips/boot/dts/mti/sead3.dts | 5 ++++- arch/mips/generic/board-sead3.c | 26 ++++++++++++++++++++------ 2 files changed, 24 insertions(+), 7 deletions(-)
diff --git a/arch/mips/boot/dts/mti/sead3.dts b/arch/mips/boot/dts/mti/sead3.dts index b112879a5d9d..60bc5f080454 100644 --- 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 = "uart1:115200"; @@ -65,6 +64,7 @@ compatible = "generic-ehci"; reg = <0x1b200000 0x1000>;
+ interrupt-parent = <&gic>; interrupts = <0>; /* GIC 0 or CPU 6 */
has-transaction-translator; @@ -227,6 +227,7 @@
clock-frequency = <14745600>;
+ interrupt-parent = <&gic>; interrupts = <3>; /* GIC 3 or CPU 4 */
no-loopback-test; @@ -241,6 +242,7 @@
clock-frequency = <14745600>;
+ interrupt-parent = <&gic>; interrupts = <2>; /* GIC 2 or CPU 4 */
no-loopback-test; @@ -251,6 +253,7 @@ 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 f4ae0584a33b..5e2f260ce16a 100644 --- a/arch/mips/generic/board-sead3.c +++ b/arch/mips/generic/board-sead3.c @@ -163,14 +163,16 @@ 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) { @@ -193,6 +195,12 @@ 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); @@ -205,6 +213,12 @@ 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);