[ALSA] hda-intel - Add check of MSI availabity

Check the availability of MSI and turn off MSI automatically when it's
not available on the hardware.  MSI seems broken on some hardwares
but the kernel doesn't know exactly, thus we have to turn the MSI
feature off on the sound driver manually.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

sound/pci/hda/hda_intel.c

@@ -337,6 +337,7 @@ struct azx {
 	unsigned int initialized :1;
 	unsigned int single_cmd :1;
 	unsigned int polling_mode :1;
+	unsigned int msi :1;
 };
 
 /* driver types */
@@ -397,6 +398,7 @@ static char *driver_short_names[] __devinitdata = {
  */
 #define upper_32bit(addr) (sizeof(addr) > 4 ? (u32)((addr) >> 32) : (u32)0)
 
+static int azx_acquire_irq(struct azx *chip, int do_disconnect);
 
 /*
  * Interface for HD codec
@@ -536,6 +538,18 @@ static unsigned int azx_rirb_get_response(struct hda_codec *codec)
 		schedule_timeout_interruptible(1);
 	} while (time_after_eq(timeout, jiffies));
 
+	if (chip->msi) {
+		snd_printk(KERN_WARNING "hda_intel: No response from codec, "
+			   "disabling MSI...\n");
+		free_irq(chip->irq, chip);
+		chip->irq = -1;
+		pci_disable_msi(chip->pci);
+		chip->msi = 0;
+		if (azx_acquire_irq(chip, 1) < 0)
+			return -1;
+		goto again;
+	}
+
 	if (!chip->polling_mode) {
 		snd_printk(KERN_WARNING "hda_intel: azx_get_response timeout, "
 			   "switching to polling mode...\n");
@@ -1364,6 +1378,20 @@ static int __devinit azx_init_stream(struct azx *chip)
 	return 0;
 }
 
+static int azx_acquire_irq(struct azx *chip, int do_disconnect)
+{
+	if (request_irq(chip->pci->irq, azx_interrupt, IRQF_DISABLED|IRQF_SHARED,
+			"HDA Intel", chip)) {
+		printk(KERN_ERR "hda-intel: unable to grab IRQ %d, "
+		       "disabling device\n", chip->pci->irq);
+		if (do_disconnect)
+			snd_card_disconnect(chip->card);
+		return -1;
+	}
+	chip->irq = chip->pci->irq;
+	return 0;
+}
+
 
 #ifdef CONFIG_PM
 /*
@@ -1385,7 +1413,7 @@ static int azx_suspend(struct pci_dev *pci, pm_message_t state)
 		free_irq(chip->irq, chip);
 		chip->irq = -1;
 	}
-	if (!disable_msi)
+	if (chip->msi)
 		pci_disable_msi(chip->pci);
 	pci_disable_device(pci);
 	pci_save_state(pci);
@@ -1407,16 +1435,11 @@ static int azx_resume(struct pci_dev *pci)
 		return -EIO;
 	}
 	pci_set_master(pci);
-	if (!disable_msi)
-		pci_enable_msi(pci);
-	if (request_irq(pci->irq, azx_interrupt, IRQF_DISABLED|IRQF_SHARED,
-			"HDA Intel", chip)) {
-		printk(KERN_ERR "hda-intel: unable to grab IRQ %d, "
-		       "disabling device\n", pci->irq);
-		snd_card_disconnect(card);
+	if (chip->msi)
+		if (pci_enable_msi(pci) < 0)
+			chip->msi = 0;
+	if (azx_acquire_irq(chip, 1) < 0)
 		return -EIO;
-	}
-	chip->irq = pci->irq;
 	azx_init_chip(chip);
 	snd_hda_resume(chip->bus);
 	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
@@ -1452,7 +1475,7 @@ static int azx_free(struct azx *chip)
 		synchronize_irq(chip->irq);
 		free_irq(chip->irq, (void*)chip);
 	}
-	if (!disable_msi)
+	if (chip->msi)
 		pci_disable_msi(chip->pci);
 	if (chip->remap_addr)
 		iounmap(chip->remap_addr);
@@ -1508,6 +1531,7 @@ static int __devinit azx_create(struct snd_card *card, struct pci_dev *pci,
 	chip->pci = pci;
 	chip->irq = -1;
 	chip->driver_type = driver_type;
+	chip->msi = !disable_msi;
 
 	chip->position_fix = position_fix;
 	chip->single_cmd = single_cmd;
@@ -1537,16 +1561,14 @@ static int __devinit azx_create(struct snd_card *card, struct pci_dev *pci,
 		goto errout;
 	}
 
-	if (!disable_msi)
-		pci_enable_msi(pci);
+	if (chip->msi)
+		if (pci_enable_msi(pci) < 0)
+			chip->msi = 0;
 
-	if (request_irq(pci->irq, azx_interrupt, IRQF_DISABLED|IRQF_SHARED,
-			"HDA Intel", (void*)chip)) {
-		snd_printk(KERN_ERR SFX "unable to grab IRQ %d\n", pci->irq);
+	if (azx_acquire_irq(chip, 0) < 0) {
 		err = -EBUSY;
 		goto errout;
 	}
-	chip->irq = pci->irq;
 
 	pci_set_master(pci);
 	synchronize_irq(chip->irq);