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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux ACPI <linux-acpi@vger.kernel.org>,
 Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
 Mika Westerberg <mika.westerberg@linux.intel.com>,
 "Rafael J. Wysocki" <rafael@kernel.org>,
 "Russell King (Oracle)" <linux@armlinux.org.uk>
Subject: [PATCH v2 1/5] ACPI: scan: Fix device check notification handling
Date: Mon, 26 Feb 2024 17:35:27 +0100
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

It is generally invalid to fail a Device Check notification if the scan
handler has not been attached to the given device after a bus rescan,
because there may be valid reasons for the scan handler to refuse
attaching to the device (for example, the device is not ready).

For this reason, modify acpi_scan_device_check() to return 0 in that
case without printing a warning.

While at it, reduce the log level of the "already enumerated" message
in the same function, because it is only interesting when debugging
notification handling

Fixes: 443fc8202272 ("ACPI / hotplug: Rework generic code to handle suprise removals")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

v1 -> v2: Add R-by from Jonathan.

---
 drivers/acpi/scan.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -314,18 +314,14 @@ static int acpi_scan_device_check(struct
 		 * again).
 		 */
 		if (adev->handler) {
-			dev_warn(&adev->dev, "Already enumerated\n");
-			return -EALREADY;
+			dev_dbg(&adev->dev, "Already enumerated\n");
+			return 0;
 		}
 		error = acpi_bus_scan(adev->handle);
 		if (error) {
 			dev_warn(&adev->dev, "Namespace scan failure\n");
 			return error;
 		}
-		if (!adev->handler) {
-			dev_warn(&adev->dev, "Enumeration failure\n");
-			error = -ENODEV;
-		}
 	} else {
 		error = acpi_scan_device_not_enumerated(adev);
 	}