ALSA: via82xx: Support PCM sync_stop

The driver invokes snd_pcm_period_elapsed() simply from the interrupt
handler.  Set card->sync_irq for enabling the missing sync_stop PCM
operation, as well as removing the superfluous synchronize_irq()
call.

Link: https://lore.kernel.org/r/20191210063454.31603-38-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/via82xx.c

@@ -2245,7 +2245,6 @@ static int snd_via82xx_suspend(struct device *dev)
 	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
 	for (i = 0; i < chip->num_devs; i++)
 		snd_via82xx_channel_reset(chip, &chip->devs[i]);
-	synchronize_irq(chip->irq);
 	snd_ac97_suspend(chip->ac97);
 
 	/* save misc values */
@@ -2376,9 +2375,9 @@ static int snd_via82xx_create(struct snd_card *card,
 		return -EBUSY;
 	}
 	chip->irq = pci->irq;
+	card->sync_irq = chip->irq;
 	if (ac97_clock >= 8000 && ac97_clock <= 48000)
 		chip->ac97_clock = ac97_clock;
-	synchronize_irq(chip->irq);
 
 	if ((err = snd_via82xx_chip_init(chip)) < 0) {
 		snd_via82xx_free(chip);

sound/pci/via82xx_modem.c

@@ -1013,7 +1013,6 @@ static int snd_via82xx_suspend(struct device *dev)
 	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
 	for (i = 0; i < chip->num_devs; i++)
 		snd_via82xx_channel_reset(chip, &chip->devs[i]);
-	synchronize_irq(chip->irq);
 	snd_ac97_suspend(chip->ac97);
 	return 0;
 }
@@ -1105,9 +1104,9 @@ static int snd_via82xx_create(struct snd_card *card,
 		return -EBUSY;
 	}
 	chip->irq = pci->irq;
+	card->sync_irq = chip->irq;
 	if (ac97_clock >= 8000 && ac97_clock <= 48000)
 		chip->ac97_clock = ac97_clock;
-	synchronize_irq(chip->irq);
 
 	if ((err = snd_via82xx_chip_init(chip)) < 0) {
 		snd_via82xx_free(chip);