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, 37 insertions, 0 deletions

diff --git a/drivers/leds/trigger/ledtrig-mtd.c b/drivers/leds/trigger/ledtrig-mtd.c
new file mode 100644
index 000000000..bbe6876a2
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-mtd.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * LED MTD trigger
+ *
+ * Copyright 2016 Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
+ *
+ * Based on LED IDE-Disk Activity Trigger
+ *
+ * Copyright 2006 Openedhand Ltd.
+ *
+ * Author: Richard Purdie <rpurdie@openedhand.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+
+#define BLINK_DELAY 30
+
+DEFINE_LED_TRIGGER(ledtrig_mtd);
+DEFINE_LED_TRIGGER(ledtrig_nand);
+
+void ledtrig_mtd_activity(void)
+{
+	led_trigger_blink_oneshot(ledtrig_mtd, BLINK_DELAY, BLINK_DELAY, 0);
+	led_trigger_blink_oneshot(ledtrig_nand, BLINK_DELAY, BLINK_DELAY, 0);
+}
+EXPORT_SYMBOL(ledtrig_mtd_activity);
+
+static int __init ledtrig_mtd_init(void)
+{
+	led_trigger_register_simple("mtd", &ledtrig_mtd);
+	led_trigger_register_simple("nand-disk", &ledtrig_nand);
+
+	return 0;
+}
+device_initcall(ledtrig_mtd_init);