diff options
| author | Bjorn Helgaas <bjorn.helgaas@hp.com> | 2013-09-23 01:51:22 (GMT) |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-09-23 23:46:23 (GMT) |
| commit | c3faedcdb41a2fedbec8ca8f8612d67b012b44a2 (patch) | |
| tree | d287953ff51e44e7f3be93d42f9d7d825b69a5ad | |
| parent | f28eb9f5009abdc74d4052ae05c01795e254a6fc (diff) | |
| download | linux-c3faedcdb41a2fedbec8ca8f8612d67b012b44a2.tar.xz | |
ACPICA: acpi_read: On error, do not modify the return value target location.
If an error happens in the middle of a split 32/32 64-bit I/O
operation, do not modify the target of the return value pointer.
Makes the code consistent with the rest of ACPICA. Bjorn Helgaas.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/acpica/hwxface.c | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c index 5ee7a814..f81fb06 100644 --- a/drivers/acpi/acpica/hwxface.c +++ b/drivers/acpi/acpica/hwxface.c @@ -119,7 +119,8 @@ ACPI_EXPORT_SYMBOL(acpi_reset) ******************************************************************************/ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg) { - u32 value; + u32 value_lo; + u32 value_hi; u32 width; u64 address; acpi_status status; @@ -137,13 +138,8 @@ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg) return (status); } - /* Initialize entire 64-bit return value to zero */ - - *return_value = 0; - value = 0; - /* - * Two address spaces supported: Memory or IO. PCI_Config is + * Two address spaces supported: Memory or I/O. PCI_Config is * not supported here because the GAS structure is insufficient */ if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { @@ -155,29 +151,35 @@ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg) } } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */ + value_lo = 0; + value_hi = 0; + width = reg->bit_width; if (width == 64) { width = 32; /* Break into two 32-bit transfers */ } status = acpi_hw_read_port((acpi_io_address) - address, &value, width); + address, &value_lo, width); if (ACPI_FAILURE(status)) { return (status); } - *return_value = value; if (reg->bit_width == 64) { /* Read the top 32 bits */ status = acpi_hw_read_port((acpi_io_address) - (address + 4), &value, 32); + (address + 4), &value_hi, + 32); if (ACPI_FAILURE(status)) { return (status); } - *return_value |= ((u64)value << 32); } + + /* Set the return value only if status is AE_OK */ + + *return_value = (value_lo | ((u64)value_hi << 32)); } ACPI_DEBUG_PRINT((ACPI_DB_IO, @@ -186,7 +188,7 @@ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg) ACPI_FORMAT_UINT64(address), acpi_ut_get_region_name(reg->space_id))); - return (status); + return (AE_OK); } ACPI_EXPORT_SYMBOL(acpi_read) |