From: Wu Fengguang <fengguang.wu@intel.com>
Date: Sat, 1 Aug 2009 10:46:46 +0000 (+0800)
Subject: ALSA: hda: take cmd_mutex in probe_codec()
X-Git-Tag: v2.6.31-rc6~65^2~6
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=a678cdee25a387c8fc3b2754974695412baf1d85

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 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);