linux/sound/hda/common
Xu Rao c139e7e44f ALSA: hda: Fix connection list comparison in proc output
print_conn_list() compares the raw hardware connection list with the
connection list cached by the HDA driver.  When they differ, it prints an
additional "In-driver Connection" line so that /proc/asound/card*/codec#*
shows the topology actually used by the driver.

The comparison currently passes conn_len directly to memcmp().  However,
conn_len is a number of connection-list entries, while memcmp() expects a
size in bytes.  Both list and conn are arrays of hda_nid_t, which is u16,
so only half of the connection data is compared.

For example, for two-entry lists such as:

  hardware: 0x0c 0x0d
  cached:   0x0c 0x0e

conn_len is 2, and the current comparison checks only the first hda_nid_t.
The lists are therefore incorrectly treated as identical even though the
second connection differs.

This can happen legitimately when codec fixups replace a cached connection
list with snd_hda_override_conn_list().  The codec routing used by the
driver is not affected, but the proc output can hide the overridden
driver-visible routing and provide misleading topology information during
codec debugging.

Convert the entry count to a byte size so that memcmp() covers the
complete connection list.

Fixes: 8b2c7a5c40 ("ALSA: hda - Add In-driver connection info")
Signed-off-by: Xu Rao <raoxu@uniontech.com>
Link: https://patch.msgid.link/7B802A4E225CC808+20260818083808.2735120-1-raoxu@uniontech.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2026-08-18 11:40:38 +02:00
..
auto_parser.c ALSA: hda: Drop index handling from snd_hda_get_pin_label() 2026-07-30 17:46:38 +02:00
beep.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
bind.c ALSA: hda: Use the new helper for PCM instance refcount 2026-06-11 09:34:09 +02:00
codec.c ALSA: hda: Drop __force casts 2026-08-13 16:43:27 +02:00
controller_trace.h
controller.c Updates for NTP/timekeeping and PTP: 2026-06-15 13:51:27 +05:30
hda_auto_parser.h ALSA: hda: Drop index handling from snd_hda_get_pin_label() 2026-07-30 17:46:38 +02:00
hda_beep.h
hda_controller.h ALSA: hda/intel: Make sure to cancel irq-pending work at closing PCM stream 2026-05-20 07:50:45 +02:00
hda_jack.h ALSA: hda - fix function names & missing function parameter 2026-01-07 09:05:50 +01:00
hda_local.h ALSA: hda: Add hda_append_suffix() local helper 2026-07-31 08:39:51 +02:00
hwdep.c
jack.c ALSA: hda: Add hda_append_suffix() local helper 2026-07-31 08:39:51 +02:00
Kconfig
Makefile
proc.c ALSA: hda: Fix connection list comparison in proc output 2026-08-18 11:40:38 +02:00
sysfs.c ALSA: hda: Relax __free() variable declarations 2025-12-17 10:08:30 +01:00