From: Takashi Iwai <tiwai@suse.de>
Subject: ALSA: Add codec bus reset and verb-retry at critical errors
Patch-mainline: 
References: bnc#502903

The Volna machine causes a severe CORB/RIRB stall when PA is started
together with fglrx.  This cannot be recovered without the controller
reset.

This patch allows the bus controller reset at critical errors so
that the communication gets recovered again.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
 sound/pci/hda/hda_codec.c |   13 +++++++++++--
 sound/pci/hda/hda_codec.h |    7 ++++++-
 sound/pci/hda/hda_intel.c |   37 +++++++++++++++++++++++++++++++++----
 3 files changed, 50 insertions(+), 7 deletions(-)

--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -541,6 +541,8 @@
 	unsigned int (*get_response)(struct hda_bus *bus);
 	/* free the private data */
 	void (*private_free)(struct hda_bus *);
+	/* reset bus for retry verb */
+	void (*bus_reset)(struct hda_bus *bus);
 #ifdef CONFIG_SND_HDA_POWER_SAVE
 	/* notify power-up/down from codec to controller */
 	void (*pm_notify)(struct hda_bus *bus);
@@ -586,6 +588,9 @@
 
 	/* misc op flags */
 	unsigned int needs_damn_long_delay :1;
+	unsigned int rirb_error:1;	/* error in codec communication */
+	unsigned int response_reset:1;	/* controller was reset */
+	unsigned int in_reset:1;	/* during reset operation */
 };
 
 /*
@@ -827,7 +832,7 @@
  * power management
  */
 #ifdef CONFIG_PM
-int snd_hda_suspend(struct hda_bus *bus, pm_message_t state);
+int snd_hda_suspend(struct hda_bus *bus);
 int snd_hda_resume(struct hda_bus *bus);
 #endif
 
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -187,6 +187,7 @@
 
 	if (res)
 		*res = -1;
+ again:
 	snd_hda_power_up(codec);
 	mutex_lock(&bus->cmd_mutex);
 	err = bus->ops.command(bus, cmd);
@@ -194,6 +195,15 @@
 		*res = bus->ops.get_response(bus);
 	mutex_unlock(&bus->cmd_mutex);
 	snd_hda_power_down(codec);
+	if (res && *res == -1 && bus->rirb_error) {
+		if (bus->response_reset) {
+			snd_printd("hda_codec: resetting BUS due to "
+				   "fatal communication error\n");
+			bus->ops.bus_reset(bus);
+		}
+		goto again;
+	}
+	bus->response_reset = 0;
 	return err;
 }
 
@@ -3279,11 +3289,10 @@
 /**
  * snd_hda_suspend - suspend the codecs
  * @bus: the HDA bus
- * @state: suspsend state
  *
  * Returns 0 if successful.
  */
-int snd_hda_suspend(struct hda_bus *bus, pm_message_t state)
+int snd_hda_suspend(struct hda_bus *bus)
 {
 	struct hda_codec *codec;
 
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -600,6 +600,7 @@
 		}
 		if (!chip->rirb.cmds) {
 			smp_rmb();
+			bus->rirb_error = 0;
 			return chip->rirb.res; /* the last value */
 		}
 		if (time_after(jiffies, timeout))
@@ -640,14 +641,23 @@
 		return -1;
 	}
 
+	/* a fatal communication error; need either to reset or to fallback
+	 * to the single_cmd mode
+	 */
+	bus->rirb_error = 1;
+	if (!bus->response_reset && !bus->in_reset) {
+		bus->response_reset = 1;
+		return -1; /* give a chance to retry */
+	}
+
 	snd_printk(KERN_ERR "hda_intel: azx_get_response timeout, "
 		   "switching to single_cmd mode: last cmd=0x%08x\n",
 		   chip->last_cmd);
-	chip->rirb.rp = azx_readb(chip, RIRBWP);
-	chip->rirb.cmds = 0;
-	/* switch to single_cmd mode */
 	chip->single_cmd = 1;
+	bus->response_reset = 0;
+	/* re-initialize CORB/RIRB */
 	azx_free_cmd_io(chip);
+	azx_init_cmd_io(chip);
 	return -1;
 }
 
@@ -688,6 +698,7 @@
 	struct azx *chip = bus->private_data;
 	int timeout = 50;
 
+	bus->rirb_error = 0;
 	while (timeout--) {
 		/* check ICB busy bit */
 		if (!((azx_readw(chip, IRS) & ICH6_IRS_BUSY))) {
@@ -1227,6 +1238,23 @@
 
 static void azx_stop_chip(struct azx *chip);
 
+static void azx_bus_reset(struct hda_bus *bus)
+{
+	struct azx *chip = bus->private_data;
+	int i;
+
+	bus->in_reset = 1;
+	azx_stop_chip(chip);
+	azx_init_chip(chip);
+	if (chip->initialized) {
+		for (i = 0; i < AZX_MAX_PCMS; i++)
+			snd_pcm_suspend_all(chip->pcm[i]);
+		snd_hda_suspend(chip->bus);
+		snd_hda_resume(chip->bus);
+	}
+	bus->in_reset = 0;
+}
+
 /*
  * Codec initialization
  */
@@ -1248,6 +1276,7 @@
 	bus_temp.pci = chip->pci;
 	bus_temp.ops.command = azx_send_cmd;
 	bus_temp.ops.get_response = azx_get_response;
+	bus_temp.ops.bus_reset = azx_bus_reset;
 #ifdef CONFIG_SND_HDA_POWER_SAVE
 	bus_temp.ops.pm_notify = azx_power_notify;
 #endif
@@ -2013,7 +2042,7 @@
 	for (i = 0; i < AZX_MAX_PCMS; i++)
 		snd_pcm_suspend_all(chip->pcm[i]);
 	if (chip->initialized)
-		snd_hda_suspend(chip->bus, state);
+		snd_hda_suspend(chip->bus);
 	azx_stop_chip(chip);
 	if (chip->irq >= 0) {
 		free_irq(chip->irq, chip);