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, 76 insertions, 0 deletions

diff --git a/include/sound/sb16_csp.h b/include/sound/sb16_csp.h
new file mode 100644
index 000000000..cafd415e2
--- /dev/null
+++ b/include/sound/sb16_csp.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *  Copyright (c) 1999 by Uros Bizjak <uros@kss-loka.si>
+ *                        Takashi Iwai <tiwai@suse.de>
+ *
+ *  SB16ASP/AWE32 CSP control
+ */
+#ifndef __SOUND_SB16_CSP_H
+#define __SOUND_SB16_CSP_H
+
+#include <sound/sb.h>
+#include <sound/hwdep.h>
+#include <linux/firmware.h>
+#include <uapi/sound/sb16_csp.h>
+
+struct snd_sb_csp;
+
+/* indices for the known CSP programs */
+enum {
+	CSP_PROGRAM_MULAW,
+	CSP_PROGRAM_ALAW,
+	CSP_PROGRAM_ADPCM_INIT,
+	CSP_PROGRAM_ADPCM_PLAYBACK,
+	CSP_PROGRAM_ADPCM_CAPTURE,
+
+	CSP_PROGRAM_COUNT
+};
+
+/*
+ * CSP operators
+ */
+struct snd_sb_csp_ops {
+	int (*csp_use) (struct snd_sb_csp * p);
+	int (*csp_unuse) (struct snd_sb_csp * p);
+	int (*csp_autoload) (struct snd_sb_csp * p, snd_pcm_format_t pcm_sfmt, int play_rec_mode);
+	int (*csp_start) (struct snd_sb_csp * p, int sample_width, int channels);
+	int (*csp_stop) (struct snd_sb_csp * p);
+	int (*csp_qsound_transfer) (struct snd_sb_csp * p);
+};
+
+/*
+ * CSP private data
+ */
+struct snd_sb_csp {
+	struct snd_sb *chip;		/* SB16 DSP */
+	int used;		/* usage flag - exclusive */
+	char codec_name[16];	/* name of codec */
+	unsigned short func_nr;	/* function number */
+	unsigned int acc_format;	/* accepted PCM formats */
+	int acc_channels;	/* accepted channels */
+	int acc_width;		/* accepted sample width */
+	int acc_rates;		/* accepted sample rates */
+	int mode;		/* MODE */
+	int run_channels;	/* current CSP channels */
+	int run_width;		/* current sample width */
+	int version;		/* CSP version (0x10 - 0x1f) */
+	int running;		/* running state */
+
+	struct snd_sb_csp_ops ops;	/* operators */
+
+	spinlock_t q_lock;	/* locking */
+	int q_enabled;		/* enabled flag */
+	int qpos_left;		/* left position */
+	int qpos_right;		/* right position */
+	int qpos_changed;	/* position changed flag */
+
+	struct snd_kcontrol *qsound_switch;
+	struct snd_kcontrol *qsound_space;
+
+	struct mutex access_mutex;	/* locking */
+
+	const struct firmware *csp_programs[CSP_PROGRAM_COUNT];
+};
+
+int snd_sb_csp_new(struct snd_sb *chip, int device, struct snd_hwdep ** rhwdep);
+#endif /* __SOUND_SB16_CSP */