| From 1e494dc5f3140005ff1f17bc06c0c16d6d50d580 Mon Sep 17 00:00:00 2001 |
| From: Mark Salter <msalter@redhat.com> |
| Date: Thu, 19 Apr 2018 23:29:47 -0400 |
| Subject: [PATCH] ACPI / scan: Fix regression related to X-Gene UARTs |
| |
| Commit e361d1f85855 ("ACPI / scan: Fix enumeration for special UART |
| devices") caused a regression with some X-Gene based platforms (Mustang |
| and M400) with invalid DSDT. The DSDT makes it appear that the UART |
| device is also a slave device attached to itself. With the above commit |
| the UART won't be enumerated by ACPI scan (slave serial devices shouldn't |
| be). So check for X-Gene UART device and skip slace device check on it. |
| |
| Signed-off-by: Mark Salter <msalter@redhat.com> |
| |
| drivers/acpi/scan.c | 8 ++++++++ |
| 1 file changed, 8 insertions(+) |
| |
| diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c |
| index e1b6231cfa1c..542dafac4306 100644 |
| |
| |
| @@ -1567,6 +1567,14 @@ static bool acpi_device_enumeration_by_parent(struct acpi_device *device) |
| if (!acpi_match_device_ids(device, i2c_multi_instantiate_ids)) |
| return false; |
| |
| + /* |
| + * Firmware on some arm64 X-Gene platforms will make the UART |
| + * device appear as both a UART and a slave of that UART. Just |
| + * bail out here for X-Gene UARTs. |
| + */ |
| + if (!strcmp(acpi_device_hid(device), "APMC0D08")) |
| + return false; |
| + |
| INIT_LIST_HEAD(&resource_list); |
| acpi_dev_get_resources(device, &resource_list, |
| acpi_check_serial_bus_slave, |
| -- |
| 2.17.1 |
| |