From dbdda4277cf0422a9ccb7ea98d0263c3cdbecdf6 Mon Sep 17 00:00:00 2001

From: Mark Salter <msalter@redhat.com>

Date: Tue, 8 May 2018 21:54:39 -0400

Subject: [PATCH] ACPI / irq: Workaround firmware issue on X-Gene based

 m400

The ACPI firmware on the xgene-based m400 platorms erroneously

describes its UART interrupt as ACPI_PRODUCER rather than

ACPI_CONSUMER. This leads to the UART driver being unable to

find its interrupt and the kernel unable find a console.

Work around this by avoiding the producer/consumer check

for X-Gene UARTs.

Signed-off-by: Mark Salter <msalter@redhat.com>

---

 drivers/acpi/irq.c | 17 +++++++++++++++--

 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c

index 7c352cba0528..028c1a564cff 100644

--- a/drivers/acpi/irq.c

+++ b/drivers/acpi/irq.c

@@ -129,6 +129,7 @@ struct acpi_irq_parse_one_ctx {

 	unsigned int index;

 	unsigned long *res_flags;

 	struct irq_fwspec *fwspec;

+	bool skip_producer_check;

 };

 /**

@@ -200,7 +201,8 @@ static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares,

 		return AE_CTRL_TERMINATE;

 	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:

 		eirq = &ares->data.extended_irq;

-		if (eirq->producer_consumer == ACPI_PRODUCER)

+		if (!ctx->skip_producer_check &&

+		    eirq->producer_consumer == ACPI_PRODUCER)

 			return AE_OK;

 		if (ctx->index >= eirq->interrupt_count) {

 			ctx->index -= eirq->interrupt_count;

@@ -235,8 +237,19 @@ static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares,

 static int acpi_irq_parse_one(acpi_handle handle, unsigned int index,

 			      struct irq_fwspec *fwspec, unsigned long *flags)

 {

-	struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec };

+	struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec, false };

+	/*

+	 * Firmware on arm64-based HPE m400 platform incorrectly marks

+	 * its UART interrupt as ACPI_PRODUCER rather than ACPI_CONSUMER.

+	 * Don't do the producer/consumer check for that device.

+	 */

+	if (IS_ENABLED(CONFIG_ARM64)) {

+		struct acpi_device *adev = acpi_bus_get_acpi_device(handle);

+

+		if (adev && !strcmp(acpi_device_hid(adev), "APMC0D08"))

+			ctx.skip_producer_check = true;

+	}

 	acpi_walk_resources(handle, METHOD_NAME__CRS, acpi_irq_parse_one_cb, &ctx;;

 	return ctx.rc;

 }

-- 

2.17.0