diff options
| author | Alexey Starikovskiy <astarikovskiy@suse.de> | 2008-01-11 02:42:51 +0300 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2008-01-10 20:49:14 -0500 |
| commit | 3e71a87d03055de0b8c8e42aba758ee6494af083 (patch) | |
| tree | a1fb6be330f06e82a1565ccbdd37a9db260dc756 | |
| parent | fd0b45dfd1858c6b49d06355a460bcf36d654c06 (diff) | |
ACPI: EC: Do the byte access with a fast path
Specification allows only byte access for EC region, so
make it separate from bug-compatible multi-byte access.
Also do not allow return of garbage in supplied *value.
Reference: http://bugzilla.kernel.org/show_bug.cgi?id=9341
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
| -rw-r--r-- | drivers/acpi/ec.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index d411017f8c0..63862dfe347 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -563,7 +563,7 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address, void *handler_context, void *region_context) { struct acpi_ec *ec = handler_context; - int result = 0, i = 0; + int result = 0, i; u8 temp = 0; if ((address > 0xFF) || !value || !handler_context) @@ -575,7 +575,16 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address, if (bits != 8 && acpi_strict) return AE_BAD_PARAMETER; - while (bits - i > 0) { + if (function == ACPI_READ) { + result = acpi_ec_read(ec, address, &temp); + *value = temp; + } else { + temp = 0xff & (*value); + result = acpi_ec_write(ec, address, temp); + } + + for (i = 8; unlikely(bits - i > 0); i += 8) { + ++address; if (function == ACPI_READ) { result = acpi_ec_read(ec, address, &temp); (*value) |= ((acpi_integer)temp) << i; @@ -583,8 +592,6 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address, temp = 0xff & ((*value) >> i); result = acpi_ec_write(ec, address, temp); } - i += 8; - ++address; } switch (result) { |