linux-kernel - [PATCH v6 1/4] ACPI / scan: Initialize status to ACPI_STA

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Message-Id: <20180809114046.21366-2-hdegoede@redhat.com>
Date:   Thu,  9 Aug 2018 13:40:43 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Len Brown <lenb@...nel.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Darren Hart <dvhart@...radead.org>,
        Wolfram Sang <wsa@...-dreams.de>
Cc:     Hans de Goede <hdegoede@...hat.com>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        linux-acpi@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        linux-i2c@...r.kernel.org
Subject: [PATCH v6 1/4] ACPI / scan: Initialize status to ACPI_STA_DEFAULT

Since commit 63347db0affa ("ACPI / scan: Use acpi_bus_get_status() to
initialize ACPI_TYPE_DEVICE devs") the status field of normal acpi_devices
gets set to 0 by acpi_bus_type_and_status() and filled with its actual
value later when acpi_add_single_object() calls acpi_bus_get_status().

This means that any acpi_match_device_ids() calls in between will always
fail with -ENOENT.

We already have a workaround for this, which temporary forces status to
ACPI_STA_DEFAULT in drivers/acpi/x86/utils.c: acpi_device_always_present()
and the next commit in this series adds another acpi_match_device_ids()
call between status being initialized as 0 and the acpi_bus_get_status()
call.

Rather then adding another workaround, this commit makes
acpi_bus_type_and_status() initialize status to ACPI_STA_DEFAULT, this is
safe to do as the only code looking at status between the initialization
and the acpi_bus_get_status() call is those acpi_match_device_ids() calls.

Note this does mean that we need to (re)set status to 0 in case the
acpi_bus_get_status() call fails.

Signed-off-by: Hans de Goede <hdegoede@...hat.com>
---
Changes in v3:
-New patch in v3 of this patch-set

Changes in v4:
-This is not a fix for acpi_is_indirect_io_slave() as I thought at first,
 acpi_is_indirect_io_slave() calls acpi_match_device_ids() on its parent
 device, where status is already set properly. Rewrite the commit message
 accordingly.
---
 drivers/acpi/scan.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 970dd87d347c..6799d00dd790 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1612,7 +1612,8 @@ static int acpi_add_single_object(struct acpi_device **child,
 	 * Note this must be done before the get power-/wakeup_dev-flags calls.
 	 */
 	if (type == ACPI_BUS_TYPE_DEVICE)
-		acpi_bus_get_status(device);
+		if (acpi_bus_get_status(device) < 0)
+			acpi_set_device_status(device, 0);

 	acpi_bus_get_power_flags(device);
 	acpi_bus_get_wakeup_device_flags(device);
@@ -1690,7 +1691,7 @@ static int acpi_bus_type_and_status(acpi_handle handle, int *type,
 		 * acpi_add_single_object updates this once we've an acpi_device
 		 * so that acpi_bus_get_status' quirk handling can be used.
 		 */
-		*sta = 0;
+		*sta = ACPI_STA_DEFAULT;
 		break;
 	case ACPI_TYPE_PROCESSOR:
 		*type = ACPI_BUS_TYPE_PROCESSOR;
-- 
2.18.0