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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2012-03-07 14:57:36 +0300 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2012-03-30 16:06:12 -0400 |
| commit | 344e222edf486bf42da1ced137e36df7a345b0ad (patch) | |
| tree | 6999f131dc4ac8b6a022ffb5b127c4eb0421cb7b | |
| parent | c264c651fd318274ffe27219947f17f24f07c073 (diff) | |
| download | blackbird-op-linux-344e222edf486bf42da1ced137e36df7a345b0ad.tar.gz blackbird-op-linux-344e222edf486bf42da1ced137e36df7a345b0ad.zip | |
ACPI throttling: fix endian bug in acpi_read_throttling_status()
Using a u64 here creates an endian bug. We store a u32 number in the
top byte which is a larger number than intended on big endian systems.
There is no reason to use a 64 bit data type here, I guess it was just
an oversight.
I removed the initialization to zero as well. It's needed with a u64
but with a u32, the variable gets initialized properly inside the call
to acpi_os_read_port().
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Len Brown <len.brown@intel.com>
| -rw-r--r-- | drivers/acpi/processor_throttling.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c index 605a2954ef17..1d02b7b5ade0 100644 --- a/drivers/acpi/processor_throttling.c +++ b/drivers/acpi/processor_throttling.c @@ -769,7 +769,7 @@ static int acpi_read_throttling_status(struct acpi_processor *pr, u64 *value) { u32 bit_width, bit_offset; - u64 ptc_value; + u32 ptc_value; u64 ptc_mask; struct acpi_processor_throttling *throttling; int ret = -1; @@ -777,12 +777,11 @@ static int acpi_read_throttling_status(struct acpi_processor *pr, throttling = &pr->throttling; switch (throttling->status_register.space_id) { case ACPI_ADR_SPACE_SYSTEM_IO: - ptc_value = 0; bit_width = throttling->status_register.bit_width; bit_offset = throttling->status_register.bit_offset; acpi_os_read_port((acpi_io_address) throttling->status_register. - address, (u32 *) &ptc_value, + address, &ptc_value, (u32) (bit_width + bit_offset)); ptc_mask = (1 << bit_width) - 1; *value = (u64) ((ptc_value >> bit_offset) & ptc_mask); |
