[PATCH v2 1/6] ACPI: RISC-V: Fix riscv_acpi_irq_get_dep() loop termination

[Lorenzo Pieralisi]

In riscv_acpi_add_irq_dep() the main loop condition would currently stop
the loop if an interrupt descriptor contains an interrupt for which the
respective GSI handle is NULL, which is not correct because subsequent
interrupts in the interrupt descriptor might still have a GSI dependency
that must not be skipped.

Rework riscv_acpi_add_irq_dep() and the riscv_acpi_irq_get_dep() call chain
to fix it - by not forcing the loop to stop in order to guarantee
dependency detection for all the interrupt entries in the CRS descriptor.

Signed-off-by: Lorenzo Pieralisi <lpieralisi at kernel.org>
Cc: "Rafael J. Wysocki" <rafael at kernel.org>
Cc: Sunil V L <sunilvl at ventanamicro.com>
---
 drivers/acpi/riscv/irq.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/riscv/irq.c b/drivers/acpi/riscv/irq.c
index 9b88d0993e88..cd83c3035cf6 100644
--- a/drivers/acpi/riscv/irq.c
+++ b/drivers/acpi/riscv/irq.c
@@ -299,6 +299,7 @@ static acpi_status riscv_acpi_irq_get_parent(struct acpi_resource *ares, void *c
 			return AE_OK;
 
 		ctx->handle = riscv_acpi_get_gsi_handle(eirq->interrupts[ctx->index]);
+		ctx->rc = 0;
 		return AE_CTRL_TERMINATE;
 	}
 
@@ -314,10 +315,8 @@ static int riscv_acpi_irq_get_dep(acpi_handle handle, unsigned int index, acpi_h
 
 	acpi_walk_resources(handle, METHOD_NAME__CRS, riscv_acpi_irq_get_parent, &ctx);
 	*gsi_handle = ctx.handle;
-	if (*gsi_handle)
-		return 1;
 
-	return 0;
+	return ctx.rc;
 }
 
 static u32 riscv_acpi_add_prt_dep(acpi_handle handle)
@@ -381,8 +380,11 @@ static u32 riscv_acpi_add_irq_dep(acpi_handle handle)
 	int i;
 
 	for (i = 0;
-	     riscv_acpi_irq_get_dep(handle, i, &gsi_handle);
+	     !riscv_acpi_irq_get_dep(handle, i, &gsi_handle);
 	     i++) {
+		if (!gsi_handle)
+			continue;
+
 		dep_devices.count = 1;
 		dep_devices.handles = kzalloc_objs(*dep_devices.handles, 1);
 		if (!dep_devices.handles) {

-- 
2.54.0