[PATCH 1/1] ACPI: EC: Allow multibyte access to EC (v2)

[Andy Whitcroft]

Allow more than a single byte to be read or written to the EC.  This
is needed by some Dell BIOSs.

Based on the original version by Alexey Starikovskiy.

BugLink: http://bugs.launchpad.net/bugs/526354
Signed-off-by: Andy Whitcroft <apw at canonical.com>
---
 drivers/acpi/acpica/exprep.c |   12 ++++++++++++
 drivers/acpi/ec.c            |    7 ++-----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/acpica/exprep.c b/drivers/acpi/acpica/exprep.c
index 52fec07..c02d543 100644
--- a/drivers/acpi/acpica/exprep.c
+++ b/drivers/acpi/acpica/exprep.c
@@ -468,6 +468,18 @@ acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
 
 		acpi_ut_add_reference(obj_desc->field.region_obj);
 
+		/* allow full data read from EC address space */
+		if (obj_desc->field.region_obj->region.space_id ==
+			ACPI_ADR_SPACE_EC) {
+			if (obj_desc->common_field.bit_length > 8)
+				obj_desc->common_field.access_bit_width =
+				ACPI_ROUND_UP(obj_desc->common_field.
+							bit_length, 8);
+				obj_desc->common_field.access_byte_width =
+				ACPI_DIV_8(obj_desc->common_field.
+							access_bit_width);
+		}
+
 		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 				  "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n",
 				  obj_desc->field.start_field_bit_offset,
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index f1670e0..b654a96 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -601,10 +601,7 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
 	if (function != ACPI_READ && function != ACPI_WRITE)
 		return AE_BAD_PARAMETER;
 
-	if (bits != 8 && acpi_strict)
-		return AE_BAD_PARAMETER;
-
-	if (EC_FLAGS_MSI)
+	if (EC_FLAGS_MSI || bits > 8)
 		acpi_ec_burst_enable(ec);
 
 	if (function == ACPI_READ) {
@@ -626,7 +623,7 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
 		}
 	}
 
-	if (EC_FLAGS_MSI)
+	if (EC_FLAGS_MSI || bits > 8)
 		acpi_ec_burst_disable(ec);
 
 	switch (result) {
-- 
1.7.0