[ALSA] #3/4 for Zoom Video - change Hardware Volume interrupt handling

Modules: ES18xx driver

Third of 4 es18xx.c patches culminating in Zoom Video support.

This patch changes the Hardware Volume support to reflect the fact that
not all of the
supported chipsets have seperate registers dedicated to the Hardware
Volume inputs. Although
all the chipsets can generate an HWV interrupt whenever a Hardware
Volume input is received
only those with seperate HWV registers can split the HWV registers from
the Master volume
registers.

Testing:
This work was initially done on the source from the Debian Sarge ALSA
package, then tested
on an ES1879 and an ES1878 machine. Patches were created against the
Sarge code and then edited
to apply correctly to the ALSA cvs code. Lastly the patched ALSA cvs
code was test for
successful compilation. No additional testing was done on the ALSA cvs
version.

Signed-off-by: Mark Salazar <markTheCoder@justmyself.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/isa/es18xx.c

@@ -148,7 +148,7 @@ struct snd_audiodrive {
 #define ES18XX_DUPLEX_SAME 0x0010	/* Playback and record must share the same rate */
 #define ES18XX_NEW_RATE	0x0020	/* More precise rate setting */
 #define ES18XX_AUXB	0x0040	/* AuxB mixer control */
-#define ES18XX_HWV	0x0080	/* Has hardware volume */
+#define ES18XX_HWV	0x0080	/* Has seperate hardware volume mixer controls*/
 #define ES18XX_MONO	0x0100	/* Mono_in mixer control */
 #define ES18XX_I2S	0x0200	/* I2S mixer control */
 #define ES18XX_MUTEREC	0x0400	/* Record source can be muted */
@@ -788,9 +788,12 @@ static irqreturn_t snd_es18xx_interrupt(int irq, void *dev_id, struct pt_regs *r
 
 	/* Hardware volume */
 	if (status & HWV_IRQ) {
-		int split = snd_es18xx_mixer_read(chip, 0x64) & 0x80;
-		snd_ctl_notify(chip->card, SNDRV_CTL_EVENT_MASK_VALUE, &chip->hw_switch->id);
-		snd_ctl_notify(chip->card, SNDRV_CTL_EVENT_MASK_VALUE, &chip->hw_volume->id);
+		int split = 0;
+		if (chip->caps & ES18XX_HWV) {
+			split = snd_es18xx_mixer_read(chip, 0x64) & 0x80;
+			snd_ctl_notify(chip->card, SNDRV_CTL_EVENT_MASK_VALUE, &chip->hw_switch->id);
+			snd_ctl_notify(chip->card, SNDRV_CTL_EVENT_MASK_VALUE, &chip->hw_volume->id);
+		}
 		if (!split) {
 			snd_ctl_notify(chip->card, SNDRV_CTL_EVENT_MASK_VALUE, &chip->master_switch->id);
 			snd_ctl_notify(chip->card, SNDRV_CTL_EVENT_MASK_VALUE, &chip->master_volume->id);
@@ -1614,22 +1617,22 @@ static int __devinit snd_es18xx_probe(struct snd_es18xx *chip)
 
 	switch (chip->version) {
 	case 0x1868:
-		chip->caps = ES18XX_DUPLEX_MONO | ES18XX_DUPLEX_SAME | ES18XX_CONTROL | ES18XX_HWV;
+		chip->caps = ES18XX_DUPLEX_MONO | ES18XX_DUPLEX_SAME | ES18XX_CONTROL;
 		break;
 	case 0x1869:
 		chip->caps = ES18XX_PCM2 | ES18XX_SPATIALIZER | ES18XX_RECMIX | ES18XX_NEW_RATE | ES18XX_AUXB | ES18XX_MONO | ES18XX_MUTEREC | ES18XX_CONTROL | ES18XX_HWV;
 		break;
 	case 0x1878:
-		chip->caps = ES18XX_DUPLEX_MONO | ES18XX_DUPLEX_SAME | ES18XX_I2S | ES18XX_CONTROL | ES18XX_HWV;
+		chip->caps = ES18XX_DUPLEX_MONO | ES18XX_DUPLEX_SAME | ES18XX_I2S | ES18XX_CONTROL;
 		break;
 	case 0x1879:
 		chip->caps = ES18XX_PCM2 | ES18XX_SPATIALIZER | ES18XX_RECMIX | ES18XX_NEW_RATE | ES18XX_AUXB | ES18XX_I2S | ES18XX_CONTROL | ES18XX_HWV;
 		break;
 	case 0x1887:
-		chip->caps = ES18XX_PCM2 | ES18XX_RECMIX | ES18XX_AUXB | ES18XX_DUPLEX_SAME | ES18XX_HWV;
+		chip->caps = ES18XX_PCM2 | ES18XX_RECMIX | ES18XX_AUXB | ES18XX_DUPLEX_SAME;
 		break;
 	case 0x1888:
-		chip->caps = ES18XX_PCM2 | ES18XX_RECMIX | ES18XX_AUXB | ES18XX_DUPLEX_SAME | ES18XX_HWV;
+		chip->caps = ES18XX_PCM2 | ES18XX_RECMIX | ES18XX_AUXB | ES18XX_DUPLEX_SAME;
 		break;
 	default:
 		snd_printk(KERN_ERR "[0x%lx] unsupported chip ES%x\n",