PNP / ACPI: Do not return errors if _DIS or _SRS are not present

The ACPI PNP subsystem returns errors from pnpacpi_set_resources()
and pnpacpi_disable_resources() if the _SRS or _DIS methods are not
present, respectively, but it should not do that, because those
methods are optional.  For this reason, modify pnpacpi_set_resources()
and pnpacpi_disable_resources(), respectively, to ignore missing _SRS
or _DIS.

This problem has been uncovered by commit 202317a573b2 (ACPI / scan:
Add acpi_device objects for all device nodes in the namespace) and
manifested itself by causing serial port suspend to fail on some
systems.

Fixes: 202317a573b2 (ACPI / scan: Add acpi_device objects for all device nodes in the namespace)
References: https://bugzilla.kernel.org/show_bug.cgi?id=74371
Reported-by: wxg4net <wxg4net@gmail.com>
Reported-and-tested-by: <nonproffessional@gmail.com>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c
index 9f611cbbc294ea8c5ae84023e132e02152e36f85..c31aa07b3ba55541ff434adf45aed76adb0adee3 100644 (file)
--- a/drivers/pnp/pnpacpi/core.c
+++ b/drivers/pnp/pnpacpi/core.c
@@ -83,8 +83,7 @@ static int pnpacpi_set_resources(struct pnp_dev *dev)
 {
        struct acpi_device *acpi_dev;
        acpi_handle handle;
-       struct acpi_buffer buffer;
-       int ret;
+       int ret = 0;
 
        pnp_dbg(&dev->dev, "set resources\n");
 
@@ -97,19 +96,26 @@ static int pnpacpi_set_resources(struct pnp_dev *dev)
        if (WARN_ON_ONCE(acpi_dev != dev->data))
                dev->data = acpi_dev;
 
-       ret = pnpacpi_build_resource_template(dev, &buffer);
-       if (ret)
-               return ret;
-       ret = pnpacpi_encode_resources(dev, &buffer);
-       if (ret) {
+       if (acpi_has_method(handle, METHOD_NAME__SRS)) {
+               struct acpi_buffer buffer;
+
+               ret = pnpacpi_build_resource_template(dev, &buffer);
+               if (ret)
+                       return ret;
+
+               ret = pnpacpi_encode_resources(dev, &buffer);
+               if (!ret) {
+                       acpi_status status;
+
+                       status = acpi_set_current_resources(handle, &buffer);
+                       if (ACPI_FAILURE(status))
+                               ret = -EIO;
+               }
                kfree(buffer.pointer);
-               return ret;
        }
-       if (ACPI_FAILURE(acpi_set_current_resources(handle, &buffer)))
-               ret = -EINVAL;
-       else if (acpi_bus_power_manageable(handle))
+       if (!ret && acpi_bus_power_manageable(handle))
                ret = acpi_bus_set_power(handle, ACPI_STATE_D0);
-       kfree(buffer.pointer);
+
        return ret;
 }
 
@@ -117,7 +123,7 @@ static int pnpacpi_disable_resources(struct pnp_dev *dev)
 {
        struct acpi_device *acpi_dev;
        acpi_handle handle;
-       int ret;
+       acpi_status status;
 
        dev_dbg(&dev->dev, "disable resources\n");
 
@@ -128,13 +134,15 @@ static int pnpacpi_disable_resources(struct pnp_dev *dev)
        }
 
        /* acpi_unregister_gsi(pnp_irq(dev, 0)); */
-       ret = 0;
        if (acpi_bus_power_manageable(handle))
                acpi_bus_set_power(handle, ACPI_STATE_D3_COLD);
-               /* continue even if acpi_bus_set_power() fails */
-       if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DIS", NULL, NULL)))
-               ret = -ENODEV;
-       return ret;
+
+       /* continue even if acpi_bus_set_power() fails */
+       status = acpi_evaluate_object(handle, "_DIS", NULL, NULL);
+       if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
+               return -ENODEV;
+
+       return 0;
 }
 
 #ifdef CONFIG_ACPI_SLEEP