[PATCH v3 1/4] ACPI / EC: Enhance boot EC sanity check

[Lv Zheng]

It's reported that some buggy BIOS tables can contain 2 DSDT ECs, one of
them is invalid but acpi_ec_dsdt_probe() fails to pick the valid one.
This patch simply enhances sanity checks in ec_parse_device() as a
workaround to skip probing wrong namespace ECs.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=195651
Tested-by: Daniel Drake <drake@xxxxxxxxxxxx>
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
 drivers/acpi/ec.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index c24235d..c1f480b 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1362,6 +1362,8 @@ ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 				     ec_parse_io_ports, ec);
 	if (ACPI_FAILURE(status))
 		return status;
+	if (ec->data_addr == 0 || ec->command_addr == 0)
+		return AE_OK;
 
 	/* Get GPE bit assignment (EC events). */
 	/* TODO: Add support for _GPE returning a package */
-- 
2.7.4