1 files changed, 55 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index bf8e6f94aebc..f3c447cf67f8 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -392,6 +392,7 @@ struct azx {
         unsigned int msi :1;
         unsigned int irq_pending_warned :1;
         unsigned int via_dmapos_patch :1; /* enable DMA-position fix for VIA */
+        unsigned int probing :1; /* codec probing phase */
 
         /* for debugging */
         unsigned int last_cmd;  /* last issued command (to sync) */
@@ -624,6 +625,14 @@ static unsigned int azx_rirb_get_response(struct hda_bus *bus)
                 goto again;
         }
 
+        if (chip->probing) {
+                /* If this critical timeout happens during the codec probing
+                 * phase, this is likely an access to a non-existing codec
+                 * slot.  Better to return an error and reset the system.
+                 */
+                return -1;
+        }
+
         snd_printk(KERN_ERR "hda_intel: azx_get_response timeout, "
                    "switching to single_cmd mode: last cmd=0x%08x\n",
                    chip->last_cmd);
@@ -1175,8 +1184,28 @@ static int azx_setup_controller(struct azx *chip, struct azx_dev *azx_dev)
         return 0;
 }
 
+/*
+ * Probe the given codec address
+ */
+static int probe_codec(struct azx *chip, int addr)
+{
+        unsigned int cmd = (addr << 28) | (AC_NODE_ROOT << 20) |
+                (AC_VERB_PARAMETERS << 8) | AC_PAR_VENDOR_ID;
+        unsigned int res;
+
+        chip->probing = 1;
+        azx_send_cmd(chip->bus, cmd);
+        res = azx_get_response(chip->bus);
+        chip->probing = 0;
+        if (res == -1)
+                return -EIO;
+        snd_printdd("hda_intel: codec #%d probed OK\n", addr);
+        return 0;
+}
+
 static int azx_attach_pcm_stream(struct hda_bus *bus, struct hda_codec *codec,
                                  struct hda_pcm *cpcm);
+static void azx_stop_chip(struct azx *chip);
 
 /*
  * Codec initialization
@@ -1216,6 +1245,32 @@ static int __devinit azx_codec_create(struct azx *chip, const char *model,
         max_slots = azx_max_codecs[chip->driver_type];
         if (!max_slots)
                 max_slots = AZX_MAX_CODECS;
+
+        /* First try to probe all given codec slots */
+        for (c = 0; c < max_slots; c++) {
+                if ((chip->codec_mask & (1 << c)) & codec_probe_mask) {
+                        if (probe_codec(chip, c) < 0) {
+                                /* Some BIOSen give you wrong codec addresses
+                                 * that don't exist
+                                 */
+                                snd_printk(KERN_WARNING
+                                           "hda_intel: Codec #%d probe error; "
+                                           "disabling it...\n", c);
+                                chip->codec_mask &= ~(1 << c);
+                                /* More badly, accessing to a non-existing
+                                 * codec often screws up the controller chip,
+                                 * and distrubs the further communications.
+                                 * Thus if an error occurs during probing,
+                                 * better to reset the controller chip to
+                                 * get back to the sanity state.
+                                 */
+                                azx_stop_chip(chip);
+                                azx_init_chip(chip);
+                        }
+                }
+        }
+
+        /* Then create codec instances */
         for (c = 0; c < max_slots; c++) {
                 if ((chip->codec_mask & (1 << c)) & codec_probe_mask) {
                         struct hda_codec *codec;