Re: [PATCH] fix pci device can't alloc irq from fdt

[Bibo Mao]

On 2025/11/11 下午3:14, Xianglai Li wrote:
When we use the -kernel parameter to start an elf format kernel relying on
fdt, we get the following error:

pcieport 0000:00:01.0: of_irq_parse_pci: failed with rc=-22
pcieport 0000:00:01.0: enabling device (0000 -> 0003)
pcieport 0000:00:01.0: PME: Signaling with IRQ 19
pcieport 0000:00:01.0: AER: enabled with IRQ 19
pcieport 0000:00:01.1: of_irq_parse_pci: failed with rc=-22
pcieport 0000:00:01.1: enabling device (0000 -> 0003)
pcieport 0000:00:01.1: PME: Signaling with IRQ 20
pcieport 0000:00:01.1: AER: enabled with IRQ 20
pcieport 0000:00:01.2: of_irq_parse_pci: failed with rc=-22
pcieport 0000:00:01.2: enabling device (0000 -> 0003)
pcieport 0000:00:01.2: PME: Signaling with IRQ 21
pcieport 0000:00:01.2: AER: enabled with IRQ 21
pcieport 0000:00:01.3: of_irq_parse_pci: failed with rc=-22
pcieport 0000:00:01.3: enabling device (0000 -> 0003)
pcieport 0000:00:01.3: PME: Signaling with IRQ 22
pcieport 0000:00:01.3: AER: enabled with IRQ 22
pcieport 0000:00:01.4: of_irq_parse_pci: failed with rc=-22

This is because the description of interrupt-cell size in the interrupt
controller pch_pic in our fdt is incorrect, and the description of
interrupt-cell is missing in the pcie irq map. Now it is corrected and
the correct interrupt-cell is added in th pcie irq map.

Signed-off-by: Xianglai Li <lixiang...@loongson.cn>
---
Cc: Bibo Mao <maob...@loongson.cn>
Cc: Jiaxun Yang <jiaxun.y...@flygoat.com>
Cc: Song Gao <gaos...@loongson.cn>

  hw/loongarch/virt-fdt-build.c | 4 +++-
  1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/loongarch/virt-fdt-build.c b/hw/loongarch/virt-fdt-build.c
index 1f0ba01f71..f1f70ed3c3 100644
--- a/hw/loongarch/virt-fdt-build.c
+++ b/hw/loongarch/virt-fdt-build.c
@@ -272,7 +272,7 @@ static void fdt_add_pch_pic_node(LoongArchVirtMachineState 
*lvms,
      qemu_fdt_setprop_cells(ms->fdt, nodename, "reg", 0,
                             pch_pic_base, 0, pch_pic_size);
      qemu_fdt_setprop(ms->fdt, nodename, "interrupt-controller", NULL, 0);
-    qemu_fdt_setprop_cell(ms->fdt, nodename, "#interrupt-cells", 2);
+    qemu_fdt_setprop_cell(ms->fdt, nodename, "#interrupt-cells", 1);
The pch_pic supports irq number and trigger level, value of 
#interrupt-cells should be 2.

      qemu_fdt_setprop_cell(ms->fdt, nodename, "interrupt-parent",
                            *eiointc_phandle);
      qemu_fdt_setprop_cell(ms->fdt, nodename, "loongson,pic-base-vec", 0);
@@ -395,6 +395,8 @@ static void fdt_add_pcie_node(const 
LoongArchVirtMachineState *lvms,
                                   2, base_mmio, 2, size_mmio);
      qemu_fdt_setprop_cells(ms->fdt, nodename, "msi-map",
                             0, *pch_msi_phandle, 0, 0x10000);
+
+    qemu_fdt_setprop_cell(ms->fdt, nodename, "#interrupt-cells", 1);
      fdt_add_pcie_irq_map_node(lvms, nodename, pch_pic_phandle);
Here is error report:
  pcieport 0000:00:01.0: of_irq_parse_pci: failed with rc=-22

I think that we should support interrupt-map fdt table in function 
fdt_add_pcie_irq_map_node(), so that PCI trigger level is added in the 
map table.

Regards
Bibo Mao
      g_free(nodename);
  }