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>

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 19e67a1b6026fa6ca7908bb1b8da10d8991ff3b4..ddabc827ac44fc2d5d50d6ec198de4b2584dceb3 100644 (file)
--- 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);