module_param(enable_loopback, bool, 0444);
 MODULE_PARM_DESC(enable_loopback, "Enable AC97 ADC/DAC Loopback Control");
 
+#ifdef CONFIG_SND_AC97_POWER_SAVE
+static int power_save;
+module_param(power_save, bool, 0644);
+MODULE_PARM_DESC(power_save, "Enable AC97 power-saving control");
+#endif
 /*
 
  */
 };
 
 
+static void update_power_regs(struct snd_ac97 *ac97);
+
 /*
  *  I/O routines
  */
        }
        err = snd_ac97_update_bits(ac97, reg, val_mask, val);
        snd_ac97_page_restore(ac97, page_save);
+#ifdef CONFIG_SND_AC97_POWER_SAVE
+       /* check analog mixer power-down */
+       if ((val_mask & 0x8000) &&
+           (kcontrol->private_value & (1<<30))) {
+               if (val & 0x8000)
+                       ac97->power_up &= ~(1 << (reg>>1));
+               else
+                       ac97->power_up |= 1 << (reg>>1);
+               if (power_save)
+                       update_power_regs(ac97);
+       }
+#endif
        return err;
 }
 
 static int snd_ac97_free(struct snd_ac97 *ac97)
 {
        if (ac97) {
+#ifdef CONFIG_SND_AC97_POWER_SAVE
+               if (ac97->power_workq)
+                       destroy_workqueue(ac97->power_workq);
+#endif
                snd_ac97_proc_done(ac97);
                if (ac97->bus)
                        ac97->bus->codec[ac97->num] = NULL;
 /*
  * create mute switch(es) for normal stereo controls
  */
-static int snd_ac97_cmute_new_stereo(struct snd_card *card, char *name, int reg, int check_stereo, struct snd_ac97 *ac97)
+static int snd_ac97_cmute_new_stereo(struct snd_card *card, char *name, int reg,
+                                    int check_stereo, int check_amix,
+                                    struct snd_ac97 *ac97)
 {
        struct snd_kcontrol *kctl;
        int err;
        }
        if (mute_mask == 0x8080) {
                struct snd_kcontrol_new tmp = AC97_DOUBLE(name, reg, 15, 7, 1, 1);
+               if (check_amix)
+                       tmp.private_value |= (1 << 30);
                tmp.index = ac97->num;
                kctl = snd_ctl_new1(&tmp, ac97);
        } else {
                struct snd_kcontrol_new tmp = AC97_SINGLE(name, reg, 15, 1, 1);
+               if (check_amix)
+                       tmp.private_value |= (1 << 30);
                tmp.index = ac97->num;
                kctl = snd_ctl_new1(&tmp, ac97);
        }
 /*
  * create a mute-switch and a volume for normal stereo/mono controls
  */
-static int snd_ac97_cmix_new_stereo(struct snd_card *card, const char *pfx, int reg, int check_stereo, struct snd_ac97 *ac97)
+static int snd_ac97_cmix_new_stereo(struct snd_card *card, const char *pfx,
+                                   int reg, int check_stereo, int check_amix,
+                                   struct snd_ac97 *ac97)
 {
        int err;
        char name[44];
 
        if (snd_ac97_try_bit(ac97, reg, 15)) {
                sprintf(name, "%s Switch", pfx);
-               if ((err = snd_ac97_cmute_new_stereo(card, name, reg, check_stereo, ac97)) < 0)
+               if ((err = snd_ac97_cmute_new_stereo(card, name, reg,
+                                                    check_stereo, check_amix,
+                                                    ac97)) < 0)
                        return err;
        }
        check_volume_resolution(ac97, reg, &lo_max, &hi_max);
        return 0;
 }
 
-#define snd_ac97_cmix_new(card, pfx, reg, ac97)        snd_ac97_cmix_new_stereo(card, pfx, reg, 0, ac97)
-#define snd_ac97_cmute_new(card, name, reg, ac97)      snd_ac97_cmute_new_stereo(card, name, reg, 0, ac97)
+#define snd_ac97_cmix_new(card, pfx, reg, acheck, ac97) \
+       snd_ac97_cmix_new_stereo(card, pfx, reg, 0, acheck, ac97)
+#define snd_ac97_cmute_new(card, name, reg, acheck, ac97) \
+       snd_ac97_cmute_new_stereo(card, name, reg, 0, acheck, ac97)
 
 static unsigned int snd_ac97_determine_spdif_rates(struct snd_ac97 *ac97);
 
        /* AD claims to remove this control from AD1887, although spec v2.2 does not allow this */
        if (snd_ac97_try_volume_mix(ac97, AC97_MASTER)) {
                if (ac97->flags & AC97_HAS_NO_MASTER_VOL)
-                       err = snd_ac97_cmute_new(card, "Master Playback Switch", AC97_MASTER, ac97);
+                       err = snd_ac97_cmute_new(card, "Master Playback Switch",
+                                                AC97_MASTER, 0, ac97);
                else
-                       err = snd_ac97_cmix_new(card, "Master Playback", AC97_MASTER, ac97);
+                       err = snd_ac97_cmix_new(card, "Master Playback",
+                                               AC97_MASTER, 0, ac97);
                if (err < 0)
                        return err;
        }
        if ((snd_ac97_try_volume_mix(ac97, AC97_SURROUND_MASTER)) 
                && !(ac97->flags & AC97_AD_MULTI)) {
                /* Surround Master (0x38) is with stereo mutes */
-               if ((err = snd_ac97_cmix_new_stereo(card, "Surround Playback", AC97_SURROUND_MASTER, 1, ac97)) < 0)
+               if ((err = snd_ac97_cmix_new_stereo(card, "Surround Playback",
+                                                   AC97_SURROUND_MASTER, 1, 0,
+                                                   ac97)) < 0)
                        return err;
        }
 
        /* build headphone controls */
        if (snd_ac97_try_volume_mix(ac97, AC97_HEADPHONE)) {
-               if ((err = snd_ac97_cmix_new(card, "Headphone Playback", AC97_HEADPHONE, ac97)) < 0)
+               if ((err = snd_ac97_cmix_new(card, "Headphone Playback",
+                                            AC97_HEADPHONE, 0, ac97)) < 0)
                        return err;
        }
        
        /* build master mono controls */
        if (snd_ac97_try_volume_mix(ac97, AC97_MASTER_MONO)) {
-               if ((err = snd_ac97_cmix_new(card, "Master Mono Playback", AC97_MASTER_MONO, ac97)) < 0)
+               if ((err = snd_ac97_cmix_new(card, "Master Mono Playback",
+                                            AC97_MASTER_MONO, 0, ac97)) < 0)
                        return err;
        }
        
        /* build Phone controls */
        if (!(ac97->flags & AC97_HAS_NO_PHONE)) {
                if (snd_ac97_try_volume_mix(ac97, AC97_PHONE)) {
-                       if ((err = snd_ac97_cmix_new(card, "Phone Playback", AC97_PHONE, ac97)) < 0)
+                       if ((err = snd_ac97_cmix_new(card, "Phone Playback",
+                                                    AC97_PHONE, 1, ac97)) < 0)
                                return err;
                }
        }
        /* build MIC controls */
        if (!(ac97->flags & AC97_HAS_NO_MIC)) {
                if (snd_ac97_try_volume_mix(ac97, AC97_MIC)) {
-                       if ((err = snd_ac97_cmix_new(card, "Mic Playback", AC97_MIC, ac97)) < 0)
+                       if ((err = snd_ac97_cmix_new(card, "Mic Playback",
+                                                    AC97_MIC, 1, ac97)) < 0)
                                return err;
                        if ((err = snd_ctl_add(card, snd_ac97_cnew(&snd_ac97_controls_mic_boost, ac97))) < 0)
                                return err;
 
        /* build Line controls */
        if (snd_ac97_try_volume_mix(ac97, AC97_LINE)) {
-               if ((err = snd_ac97_cmix_new(card, "Line Playback", AC97_LINE, ac97)) < 0)
+               if ((err = snd_ac97_cmix_new(card, "Line Playback",
+                                            AC97_LINE, 1, ac97)) < 0)
                        return err;
        }
        
        /* build CD controls */
        if (!(ac97->flags & AC97_HAS_NO_CD)) {
                if (snd_ac97_try_volume_mix(ac97, AC97_CD)) {
-                       if ((err = snd_ac97_cmix_new(card, "CD Playback", AC97_CD, ac97)) < 0)
+                       if ((err = snd_ac97_cmix_new(card, "CD Playback",
+                                                    AC97_CD, 1, ac97)) < 0)
                                return err;
                }
        }
        /* build Video controls */
        if (!(ac97->flags & AC97_HAS_NO_VIDEO)) {
                if (snd_ac97_try_volume_mix(ac97, AC97_VIDEO)) {
-                       if ((err = snd_ac97_cmix_new(card, "Video Playback", AC97_VIDEO, ac97)) < 0)
+                       if ((err = snd_ac97_cmix_new(card, "Video Playback",
+                                                    AC97_VIDEO, 1, ac97)) < 0)
                                return err;
                }
        }
        /* build Aux controls */
        if (!(ac97->flags & AC97_HAS_NO_AUX)) {
                if (snd_ac97_try_volume_mix(ac97, AC97_AUX)) {
-                       if ((err = snd_ac97_cmix_new(card, "Aux Playback", AC97_AUX, ac97)) < 0)
+                       if ((err = snd_ac97_cmix_new(card, "Aux Playback",
+                                                    AC97_AUX, 1, ac97)) < 0)
                                return err;
                }
        }
        } else {
                if (!(ac97->flags & AC97_HAS_NO_STD_PCM)) {
                        if (ac97->flags & AC97_HAS_NO_PCM_VOL)
-                               err = snd_ac97_cmute_new(card, "PCM Playback Switch", AC97_PCM, ac97);
+                               err = snd_ac97_cmute_new(card,
+                                                        "PCM Playback Switch",
+                                                        AC97_PCM, 0, ac97);
                        else
-                               err = snd_ac97_cmix_new(card, "PCM Playback", AC97_PCM, ac97);
+                               err = snd_ac97_cmix_new(card, "PCM Playback",
+                                                       AC97_PCM, 0, ac97);
                        if (err < 0)
                                return err;
                }
                if ((err = snd_ctl_add(card, snd_ac97_cnew(&snd_ac97_control_capture_src, ac97))) < 0)
                        return err;
                if (snd_ac97_try_bit(ac97, AC97_REC_GAIN, 15)) {
-                       if ((err = snd_ac97_cmute_new(card, "Capture Switch", AC97_REC_GAIN, ac97)) < 0)
+                       err = snd_ac97_cmute_new(card, "Capture Switch",
+                                                AC97_REC_GAIN, 0, ac97);
+                       if (err < 0)
                                return err;
                }
                if ((err = snd_ctl_add(card, snd_ac97_cnew(&snd_ac97_control_capture_vol, ac97))) < 0)
 /* build_ops to do nothing */
 static struct snd_ac97_build_ops null_build_ops;
 
+#ifdef CONFIG_SND_AC97_POWER_SAVE
+static void do_update_power(void *data)
+{
+       update_power_regs(data);
+}
+#endif
+
 /**
  * snd_ac97_mixer - create an Codec97 component
  * @bus: the AC97 bus which codec is attached to
        bus->codec[ac97->num] = ac97;
        mutex_init(&ac97->reg_mutex);
        mutex_init(&ac97->page_mutex);
+#ifdef CONFIG_SND_AC97_POWER_SAVE
+       ac97->power_workq = create_workqueue("ac97");
+       INIT_WORK(&ac97->power_work, do_update_power, ac97);
+#endif
 
 #ifdef CONFIG_PCI
        if (ac97->pci) {
                        return -ENOMEM;
                }
        }
-       /* make sure the proper powerdown bits are cleared */
-       if (ac97->scaps && ac97_is_audio(ac97)) {
-               reg = snd_ac97_read(ac97, AC97_EXTENDED_STATUS);
-               if (ac97->scaps & AC97_SCAP_SURROUND_DAC) 
-                       reg &= ~AC97_EA_PRJ;
-               if (ac97->scaps & AC97_SCAP_CENTER_LFE_DAC) 
-                       reg &= ~(AC97_EA_PRI | AC97_EA_PRK);
-               snd_ac97_write_cache(ac97, AC97_EXTENDED_STATUS, reg);
-       }
+       if (ac97_is_audio(ac97))
+               update_power_regs(ac97);
        snd_ac97_proc_init(ac97);
        if ((err = snd_device_new(card, SNDRV_DEV_CODEC, ac97, &ops)) < 0) {
                snd_ac97_free(ac97);
                snd_ac97_write(ac97, AC97_HEADPHONE, 0x9f9f);
        }
 
-       power = ac97->regs[AC97_POWERDOWN] | 0x8000;    /* EAPD */
-       power |= 0x4000;        /* Headphone amplifier powerdown */
-       power |= 0x0300;        /* ADC & DAC powerdown */
+       /* surround, CLFE, mic powerdown */
+       power = ac97->regs[AC97_EXTENDED_STATUS];
+       if (ac97->scaps & AC97_SCAP_SURROUND_DAC)
+               power |= AC97_EA_PRJ;
+       if (ac97->scaps & AC97_SCAP_CENTER_LFE_DAC)
+               power |= AC97_EA_PRI | AC97_EA_PRK;
+       power |= AC97_EA_PRL;
+       snd_ac97_write(ac97, AC97_EXTENDED_STATUS, power);
+
+       /* powerdown external amplifier */
+       if (ac97->scaps & AC97_SCAP_INV_EAPD)
+               power = ac97->regs[AC97_POWERDOWN] & ~AC97_PD_EAPD;
+       else if (! (ac97->scaps & AC97_SCAP_EAPD_LED))
+               power = ac97->regs[AC97_POWERDOWN] | AC97_PD_EAPD;
+       power |= AC97_PD_PR6;   /* Headphone amplifier powerdown */
+       power |= AC97_PD_PR0 | AC97_PD_PR1;     /* ADC & DAC powerdown */
        snd_ac97_write(ac97, AC97_POWERDOWN, power);
        udelay(100);
-       power |= 0x0400;        /* Analog Mixer powerdown (Vref on) */
-       snd_ac97_write(ac97, AC97_POWERDOWN, power);
-       udelay(100);
-#if 0
-       /* FIXME: this causes click noises on some boards at resume */
-       power |= 0x3800;        /* AC-link powerdown, internal Clk disable */
+       power |= AC97_PD_PR2 | AC97_PD_PR3;     /* Analog Mixer powerdown */
        snd_ac97_write(ac97, AC97_POWERDOWN, power);
+#ifdef CONFIG_SND_AC97_POWER_SAVE
+       if (power_save) {
+               udelay(100);
+               /* AC-link powerdown, internal Clk disable */
+               /* FIXME: this may cause click noises on some boards */
+               power |= AC97_PD_PR4 | AC97_PD_PR5;
+               snd_ac97_write(ac97, AC97_POWERDOWN, power);
+       }
 #endif
 }
 
 
+struct ac97_power_reg {
+       unsigned short reg;
+       unsigned short power_reg;
+       unsigned short mask;
+};
+
+enum { PWIDX_ADC, PWIDX_FRONT, PWIDX_CLFE, PWIDX_SURR, PWIDX_MIC, PWIDX_SIZE };
+
+static struct ac97_power_reg power_regs[PWIDX_SIZE] = {
+       [PWIDX_ADC] = { AC97_PCM_LR_ADC_RATE, AC97_POWERDOWN, AC97_PD_PR0},
+       [PWIDX_FRONT] = { AC97_PCM_FRONT_DAC_RATE, AC97_POWERDOWN, AC97_PD_PR1},
+       [PWIDX_CLFE] = { AC97_PCM_LFE_DAC_RATE, AC97_EXTENDED_STATUS,
+                        AC97_EA_PRI | AC97_EA_PRK},
+       [PWIDX_SURR] = { AC97_PCM_SURR_DAC_RATE, AC97_EXTENDED_STATUS,
+                        AC97_EA_PRJ},
+       [PWIDX_MIC] = { AC97_PCM_MIC_ADC_RATE, AC97_EXTENDED_STATUS,
+                       AC97_EA_PRL},
+};
+
+#ifdef CONFIG_SND_AC97_POWER_SAVE
+/**
+ * snd_ac97_update_power - update the powerdown register
+ * @ac97: the codec instance
+ * @reg: the rate register, e.g. AC97_PCM_FRONT_DAC_RATE
+ * @powerup: non-zero when power up the part
+ *
+ * Update the AC97 powerdown register bits of the given part.
+ */
+int snd_ac97_update_power(struct snd_ac97 *ac97, int reg, int powerup)
+{
+       int i;
+
+       if (! ac97)
+               return 0;
+
+       if (reg) {
+               /* SPDIF requires DAC power, too */
+               if (reg == AC97_SPDIF)
+                       reg = AC97_PCM_FRONT_DAC_RATE;
+               for (i = 0; i < PWIDX_SIZE; i++) {
+                       if (power_regs[i].reg == reg) {
+                               if (powerup)
+                                       ac97->power_up |= (1 << i);
+                               else
+                                       ac97->power_up &= ~(1 << i);
+                               break;
+                       }
+               }
+       }
+
+       if (! power_save)
+               return 0;
+
+       if (! powerup && ac97->power_workq)
+               /* adjust power-down bits after two seconds delay
+                * (for avoiding loud click noises for many (OSS) apps
+                *  that open/close frequently)
+                */
+               queue_delayed_work(ac97->power_workq, &ac97->power_work, HZ*2);
+       else
+               update_power_regs(ac97);
+
+       return 0;
+}
+
+EXPORT_SYMBOL(snd_ac97_update_power);
+#endif /* CONFIG_SND_AC97_POWER_SAVE */
+
+static void update_power_regs(struct snd_ac97 *ac97)
+{
+       unsigned int power_up, bits;
+       int i;
+
+#ifdef CONFIG_SND_AC97_POWER_SAVE
+       if (power_save)
+               power_up = ac97->power_up;
+       else {
+#endif
+               power_up = (1 << PWIDX_FRONT) | (1 << PWIDX_ADC);
+               power_up |= (1 << PWIDX_MIC);
+               if (ac97->scaps & AC97_SCAP_SURROUND_DAC)
+                       power_up |= (1 << PWIDX_SURR);
+               if (ac97->scaps & AC97_SCAP_CENTER_LFE_DAC)
+                       power_up |= (1 << PWIDX_CLFE);
+#ifdef CONFIG_SND_AC97_POWER_SAVE
+       }
+#endif
+       if (power_up) {
+               if (ac97->regs[AC97_POWERDOWN] & AC97_PD_PR2) {
+                       /* needs power-up analog mix and vref */
+                       snd_ac97_update_bits(ac97, AC97_POWERDOWN,
+                                            AC97_PD_PR3, 0);
+                       msleep(1);
+                       snd_ac97_update_bits(ac97, AC97_POWERDOWN,
+                                            AC97_PD_PR2, 0);
+               }
+       }
+       for (i = 0; i < PWIDX_SIZE; i++) {
+               if (power_up & (1 << i))
+                       bits = 0;
+               else
+                       bits = power_regs[i].mask;
+               snd_ac97_update_bits(ac97, power_regs[i].power_reg,
+                                    power_regs[i].mask, bits);
+       }
+       if (! power_up) {
+               if (! (ac97->regs[AC97_POWERDOWN] & AC97_PD_PR2)) {
+                       /* power down analog mix and vref */
+                       snd_ac97_update_bits(ac97, AC97_POWERDOWN,
+                                            AC97_PD_PR2, AC97_PD_PR2);
+                       snd_ac97_update_bits(ac97, AC97_POWERDOWN,
+                                            AC97_PD_PR3, AC97_PD_PR3);
+               }
+       }
+}
+
+
 #ifdef CONFIG_PM
 /**
  * snd_ac97_suspend - General suspend function for AC97 codec
        msw->put = master_mute_sw_put;
        snd_ac97_remove_ctl(ac97, "External Amplifier", NULL);
        snd_ac97_update_bits(ac97, AC97_POWERDOWN, 0x8000, 0x8000); /* mute LED on */
+       ac97->scaps |= AC97_SCAP_EAPD_LED;
        return 0;
 }