From: Takashi Iwai <tiwai@suse.de>
Subject: ALSA: hda - Always sync writes in single_cmd mode
Patch-mainline: 
References: bnc#502903

In the single_cmd mode, the hardware cannot store the multiple replies
like on RIRB, thus each verb has to sync and wait for the response no
matter whether the return value is needed or not.  Otherwise it may
result in a wrong return value from the previous verb.

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

---
 sound/pci/hda/hda_intel.c |   36 +++++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 13 deletions(-)

--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -661,6 +661,27 @@
  *       I left the codes, however, for debugging/testing purposes.
  */
 
+/* receive a response */
+static int azx_single_wait_for_response(struct azx *chip)
+{
+	int timeout = 50;
+
+	while (timeout--) {
+		/* check IRV busy bit */
+		if (azx_readw(chip, IRS) & ICH6_IRS_VALID) {
+			/* reuse rirb.res as the response return value */
+			chip->rirb.res = azx_readl(chip, IR);
+			return 0;
+		}
+		udelay(1);
+	}
+	if (printk_ratelimit())
+		snd_printd(SFX "get_response timeout: IRS=0x%x\n",
+			   azx_readw(chip, IRS));
+	chip->rirb.res = -1;
+	return -EIO;
+}
+
 /* send a command */
 static int azx_single_send_cmd(struct hda_bus *bus, u32 val)
 {
@@ -676,7 +697,7 @@
 			azx_writel(chip, IC, val);
 			azx_writew(chip, IRS, azx_readw(chip, IRS) |
 				   ICH6_IRS_BUSY);
-			return 0;
+			return azx_single_wait_for_response(chip);
 		}
 		udelay(1);
 	}
@@ -690,18 +711,7 @@
 static unsigned int azx_single_get_response(struct hda_bus *bus)
 {
 	struct azx *chip = bus->private_data;
-	int timeout = 50;
-
-	while (timeout--) {
-		/* check IRV busy bit */
-		if (azx_readw(chip, IRS) & ICH6_IRS_VALID)
-			return azx_readl(chip, IR);
-		udelay(1);
-	}
-	if (printk_ratelimit())
-		snd_printd(SFX "get_response timeout: IRS=0x%x\n",
-			   azx_readw(chip, IRS));
-	return (unsigned int)-1;
+	return chip->rirb.res;
 }
 
 /*