x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 60 insertions, 0 deletions

diff --git a/drivers/hid/hid-xinmo.c b/drivers/hid/hid-xinmo.c
new file mode 100644
index 000000000..66b8bfb6e
--- /dev/null
+++ b/drivers/hid/hid-xinmo.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID driver for Xin-Mo devices, currently only the Dual Arcade controller.
+ *  Fixes the negative axis event values (the devices sends -2) to match the
+ *  logical axis minimum of the HID report descriptor (the report announces
+ *  -1). It is needed because hid-input discards out of bounds values.
+ *  (This module is based on "hid-saitek" and "hid-lg".)
+ *
+ *  Copyright (c) 2013 Olivier Scherler
+ */
+
+/*
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+#include "hid-ids.h"
+
+/*
+ * Fix negative events that are out of bounds.
+ */
+static int xinmo_event(struct hid_device *hdev, struct hid_field *field,
+		struct hid_usage *usage, __s32 value)
+{
+	switch (usage->code) {
+	case ABS_X:
+	case ABS_Y:
+	case ABS_Z:
+	case ABS_RX:
+		if (value < -1) {
+			input_event(field->hidinput->input, usage->type,
+				usage->code, -1);
+			return 1;
+		}
+		break;
+	}
+
+	return 0;
+}
+
+static const struct hid_device_id xinmo_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_XIN_MO, USB_DEVICE_ID_XIN_MO_DUAL_ARCADE) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_XIN_MO, USB_DEVICE_ID_THT_2P_ARCADE) },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(hid, xinmo_devices);
+
+static struct hid_driver xinmo_driver = {
+	.name = "xinmo",
+	.id_table = xinmo_devices,
+	.event = xinmo_event
+};
+
+module_hid_driver(xinmo_driver);
+MODULE_DESCRIPTION("HID driver for Xin-Mo devices");
+MODULE_LICENSE("GPL");