linux-kernel - [PATCH 4/6] platform/x86: wmi: Fix probe failure when failing to register WMI devices

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Message-Id: <20231007233933.72121-5-W_Armin@gmx.de>
Date:   Sun,  8 Oct 2023 01:39:31 +0200
From:   Armin Wolf <W_Armin@....de>
To:     hdegoede@...hat.com, markgross@...nel.org,
        ilpo.jarvinen@...ux.intel.com
Cc:     platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 4/6] platform/x86: wmi: Fix probe failure when failing to register WMI devices

When a WMI device besides the first one somehow fails to register, retval
is returned while still containing a negative error code. This causes the
ACPI device failing to probe, leaving behind zombie WMI devices leading
to various errors later.
Fix this by handling the single error path separately and return 0 after
trying to register all WMI devices. Also continue to register WMI devices
even if some fail to allocate.

Fixes: 6ee50aaa9a20 ("platform/x86: wmi: Instantiate all devices before adding them")
Signed-off-by: Armin Wolf <W_Armin@....de>
---
 drivers/platform/x86/wmi.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index e3984801883a..ab24ea9ffc9a 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -1338,8 +1338,8 @@ static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
 	struct wmi_block *wblock;
 	union acpi_object *obj;
 	acpi_status status;
-	int retval = 0;
 	u32 i, total;
+	int retval;

 	status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
 	if (ACPI_FAILURE(status))
@@ -1350,8 +1350,8 @@ static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
 		return -ENXIO;

 	if (obj->type != ACPI_TYPE_BUFFER) {
-		retval = -ENXIO;
-		goto out_free_pointer;
+		kfree(obj);
+		return -ENXIO;
 	}

 	gblock = (const struct guid_block *)obj->buffer.pointer;
@@ -1366,8 +1366,8 @@ static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)

 		wblock = kzalloc(sizeof(*wblock), GFP_KERNEL);
 		if (!wblock) {
-			retval = -ENOMEM;
-			break;
+			dev_err(wmi_bus_dev, "Failed to allocate %pUL\n", &gblock[i].guid);
+			continue;
 		}

 		wblock->acpi_device = device;
@@ -1398,9 +1398,9 @@ static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
 		}
 	}

-out_free_pointer:
-	kfree(out.pointer);
-	return retval;
+	kfree(obj);
+
+	return 0;
 }

 /*
--
2.39.2