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, 101 insertions, 0 deletions

diff --git a/drivers/hid/hid-rapoo.c b/drivers/hid/hid-rapoo.c
new file mode 100644
index 000000000..5c9c396fa
--- /dev/null
+++ b/drivers/hid/hid-rapoo.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <asm-generic/errno-base.h>
+#include <asm-generic/int-ll64.h>
+#include <linux/bitops.h>
+#include <linux/input.h>
+#include <linux/input-event-codes.h>
+#include <linux/module.h>
+#include <linux/hid.h>
+#include <linux/usb.h>
+
+#include "hid-ids.h"
+
+#define RAPOO_BTN_BACK			0x08
+#define RAPOO_BTN_FORWARD		0x10
+
+static const struct hid_device_id rapoo_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_RAPOO, USB_DEVICE_ID_RAPOO_2_4G_RECEIVER) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, rapoo_devices);
+
+static int rapoo_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	int ret;
+	struct input_dev *input;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "parse failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (ret) {
+		hid_err(hdev, "start failed\n");
+		return ret;
+	}
+
+	if (hid_is_usb(hdev)) {
+		struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
+
+		if (intf->cur_altsetting->desc.bInterfaceNumber != 1)
+			return 0;
+	}
+
+	input = devm_input_allocate_device(&hdev->dev);
+	if (!input)
+		return -ENOMEM;
+
+	input->name = "Rapoo 2.4G Wireless Mouse";
+	input->phys = "rapoo/input1";
+	input->id.bustype = hdev->bus;
+	input->id.vendor = hdev->vendor;
+	input->id.product = hdev->product;
+	input->id.version = hdev->version;
+
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(KEY_BACK, input->keybit);
+	__set_bit(KEY_FORWARD, input->keybit);
+
+	ret = input_register_device(input);
+	if (ret)
+		return ret;
+
+	hid_set_drvdata(hdev, input);
+
+	return ret;
+}
+
+static int rapoo_raw_event(struct hid_device *hdev, struct hid_report *report, u8 *data, int size)
+{
+	struct input_dev *input = hid_get_drvdata(hdev);
+
+	if (!input)
+		return 0;
+
+	if (report->id == 1 && size >= 2) {
+		u8 btn = data[1];
+
+		input_report_key(input, KEY_BACK, btn & RAPOO_BTN_BACK);
+		input_report_key(input, KEY_FORWARD, btn & RAPOO_BTN_FORWARD);
+		input_sync(input);
+		return 1;
+	}
+
+	return 0;
+}
+
+static struct hid_driver rapoo_driver = {
+	.name = "hid-rapoo",
+	.id_table = rapoo_devices,
+	.probe = rapoo_probe,
+	.raw_event = rapoo_raw_event,
+};
+
+module_hid_driver(rapoo_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Nguyen Dinh Dang Duong <dangduong31205@gmail.com>");
+MODULE_DESCRIPTION("RAPOO 2.4G Wireless Device Driver");
+