ALSA: hda: take cmd_mutex in probe_codec()

Now that each codec will have its own module, it is possible
for the user to load one codec while another one is running.

So cmd_mutex would be a safe addition to probe_codec().

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 19e67a1b6026..ddabc827ac44 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1275,10 +1275,12 @@ static int probe_codec(struct azx *chip, int addr)
                 (AC_VERB_PARAMETERS << 8) | AC_PAR_VENDOR_ID;
         unsigned int res;
 
+        mutex_lock(&chip->bus->cmd_mutex);
         chip->probing = 1;
         azx_send_cmd(chip->bus, cmd);
         res = azx_get_response(chip->bus, addr);
         chip->probing = 0;
+        mutex_unlock(&chip->bus->cmd_mutex);
         if (res == -1)
                 return -EIO;
         snd_printdd(SFX "codec #%d probed OK\n", addr);