Re: [PATCH] ACPI: EC: limit multibyte access to EC to 8 byte

From: Alexey Starikovskiy
Date: Fri Apr 16 2010 - 13:24:47 EST


Hi Alexander,

Thanks, but we already have patch to do just that.
See https://bugzilla.kernel.org/show_bug.cgi?id=15749

Regards,
Alex.

16.04.2010 20:07, Alexander Rauth ÐÐÑÐÑ:
commit dadf28a10c3eb29421837a2e413ab869ebd9e168 enabled multibyte
access to EC, but ignored that the consuming function expects the
bitfields to be in chunks of maximal 64 bit. So limit multibyte
access to 8 byte to prevent error in the ACPI layer.

Signed-off-by: Alexander Rauth<alexander.rauth@xxxxxxxxxxxxxxx>
---
drivers/acpi/acpica/exprep.c | 17 +++++++++++------
1 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/acpica/exprep.c b/drivers/acpi/acpica/exprep.c
index a610ebe..58659af 100644
--- a/drivers/acpi/acpica/exprep.c
+++ b/drivers/acpi/acpica/exprep.c
@@ -471,13 +471,18 @@ acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info)
/* 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);
+ if (obj_desc->common_field.bit_length> 8) {
+ if (obj_desc->common_field.bit_length<= 64) {
+ obj_desc->common_field.access_bit_width =
+ ACPI_ROUND_UP(obj_desc->common_field.
+ bit_length, 8);
+ } else {
+ obj_desc->common_field.access_bit_width = 64;
+ }
obj_desc->common_field.access_byte_width =
- ACPI_DIV_8(obj_desc->common_field.
- access_bit_width);
+ ACPI_DIV_8(obj_desc->common_field.
+ access_bit_width);
+ }
}

ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,

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