Merge tag 'pm+acpi-3.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management fixes from Rafael Wysocki:
 "These are regression fixes (ACPI hotplug, cpufreq, hibernation, ACPI
  LPSS driver), fixes for stuff that never worked correctly (ACPI GPIO
  support in some cases and a wrong sign of an error code in the ACPI
  core in one place), and one blacklist item for ACPI backlight
  handling.

  Specifics:

   - Revert of a recent hibernation core commit that introduced a NULL
     pointer dereference during resume for at least one user (Rafael J
     Wysocki).

   - Fix for the ACPI LPSS (Low-Power Subsystem) driver to disable
     asynchronous PM callback execution for LPSS devices during system
     suspend/resume (introduced in 3.16) which turns out to break
     ordering expectations on some systems.  From Fu Zhonghui.

   - cpufreq core fix related to the handling of sysfs nodes during
     system suspend/resume that has been broken for intel_pstate since
     3.15 from Lan Tianyu.

   - Restore the generation of "online" uevents for ACPI container
     devices that was removed in 3.14, but some user space utilities
     turn out to need them (Rafael J Wysocki).

   - The cpufreq core fails to release a lock in an error code path
     after changes made in 3.14.  Fix from Prarit Bhargava.

   - ACPICA and ACPI/GPIO fixes to make the handling of ACPI GPIO
     operation regions (which means AML using GPIOs) work correctly in
     all cases from Bob Moore and Srinivas Pandruvada.

   - Fix for a wrong sign of the ACPI core's create_modalias() return
     value in case of an error from Mika Westerberg.

   - ACPI backlight blacklist entry for ThinkPad X201s from Aaron Lu"

* tag 'pm+acpi-3.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "PM / Hibernate: Iterate over set bits instead of PFNs in swsusp_free()"
  gpio / ACPI: Use pin index and bit length
  ACPICA: Update to GPIO region handler interface.
  ACPI / platform / LPSS: disable async suspend/resume of LPSS devices
  cpufreq: release policy->rwsem on error
  cpufreq: fix cpufreq suspend/resume for intel_pstate
  ACPI / scan: Correct error return value of create_modalias()
  ACPI / video: disable native backlight for ThinkPad X201s
  ACPI / hotplug: Generate online uevents for ACPI containers

1 files changed, 67 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/exfield.c b/drivers/acpi/acpica/exfield.c
index 6907ce0c704c..b994845ed359 100644
--- a/drivers/acpi/acpica/exfield.c
+++ b/drivers/acpi/acpica/exfield.c
@@ -253,6 +253,37 @@ acpi_ex_read_data_from_field(struct acpi_walk_state * walk_state,
 		buffer = &buffer_desc->integer.value;
 	}
 
+	if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
+	    (obj_desc->field.region_obj->region.space_id ==
+	     ACPI_ADR_SPACE_GPIO)) {
+		/*
+		 * For GPIO (general_purpose_io), the Address will be the bit offset
+		 * from the previous Connection() operator, making it effectively a
+		 * pin number index. The bit_length is the length of the field, which
+		 * is thus the number of pins.
+		 */
+		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
+				  "GPIO FieldRead [FROM]:  Pin %u Bits %u\n",
+				  obj_desc->field.pin_number_index,
+				  obj_desc->field.bit_length));
+
+		/* Lock entire transaction if requested */
+
+		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
+
+		/* Perform the write */
+
+		status = acpi_ex_access_region(obj_desc, 0,
+					       (u64 *)buffer, ACPI_READ);
+		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
+		if (ACPI_FAILURE(status)) {
+			acpi_ut_remove_reference(buffer_desc);
+		} else {
+			*ret_buffer_desc = buffer_desc;
+		}
+		return_ACPI_STATUS(status);
+	}
+
 	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 			  "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
 			  obj_desc, obj_desc->common.type, buffer,
@@ -413,6 +444,42 @@ acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
 
 		*result_desc = buffer_desc;
 		return_ACPI_STATUS(status);
+	} else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
+		   (obj_desc->field.region_obj->region.space_id ==
+		    ACPI_ADR_SPACE_GPIO)) {
+		/*
+		 * For GPIO (general_purpose_io), we will bypass the entire field
+		 * mechanism and handoff the bit address and bit width directly to
+		 * the handler. The Address will be the bit offset
+		 * from the previous Connection() operator, making it effectively a
+		 * pin number index. The bit_length is the length of the field, which
+		 * is thus the number of pins.
+		 */
+		if (source_desc->common.type != ACPI_TYPE_INTEGER) {
+			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
+		}
+
+		ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
+				  "GPIO FieldWrite [FROM]: (%s:%X), Val %.8X  [TO]:  Pin %u Bits %u\n",
+				  acpi_ut_get_type_name(source_desc->common.
+							type),
+				  source_desc->common.type,
+				  (u32)source_desc->integer.value,
+				  obj_desc->field.pin_number_index,
+				  obj_desc->field.bit_length));
+
+		buffer = &source_desc->integer.value;
+
+		/* Lock entire transaction if requested */
+
+		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
+
+		/* Perform the write */
+
+		status = acpi_ex_access_region(obj_desc, 0,
+					       (u64 *)buffer, ACPI_WRITE);
+		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
+		return_ACPI_STATUS(status);
 	}
 
 	/* Get a pointer to the data to be written */