sound: oxygen: cache codec registers

Keep a cache of codec registers to avoid unnecessary writes.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

4 files changed, 250 insertions, 152 deletions

diff --git a/sound/pci/oxygen/hifier.c b/sound/pci/oxygen/hifier.c
index 19e9e0123304..2079c100aabc 100644
--- a/sound/pci/oxygen/hifier.c
+++ b/sound/pci/oxygen/hifier.c
@@ -57,23 +57,28 @@ static struct pci_device_id hifier_ids[] __devinitdata = {
 MODULE_DEVICE_TABLE(pci, hifier_ids);
 
 struct hifier_data {
-        u8 ak4396_ctl2;
+        u8 ak4396_regs[5];
 };
 
 static void ak4396_write(struct oxygen *chip, u8 reg, u8 value)
 {
+        struct hifier_data *data = chip->model_data;
+
         oxygen_write_spi(chip, OXYGEN_SPI_TRIGGER  |
                          OXYGEN_SPI_DATA_LENGTH_2 |
                          OXYGEN_SPI_CLOCK_160 |
                          (0 << OXYGEN_SPI_CODEC_SHIFT) |
                          OXYGEN_SPI_CEN_LATCH_CLOCK_HI,
                          AK4396_WRITE | (reg << 8) | value);
+        data->ak4396_regs[reg] = value;
 }
 
-static void update_ak4396_volume(struct oxygen *chip)
+static void ak4396_write_cached(struct oxygen *chip, u8 reg, u8 value)
 {
-        ak4396_write(chip, AK4396_LCH_ATT, chip->dac_volume[0]);
-        ak4396_write(chip, AK4396_RCH_ATT, chip->dac_volume[1]);
+        struct hifier_data *data = chip->model_data;
+
+        if (value != data->ak4396_regs[reg])
+                ak4396_write(chip, reg, value);
 }
 
 static void hifier_registers_init(struct oxygen *chip)
@@ -81,16 +86,19 @@ static void hifier_registers_init(struct oxygen *chip)
         struct hifier_data *data = chip->model_data;
 
         ak4396_write(chip, AK4396_CONTROL_1, AK4396_DIF_24_MSB | AK4396_RSTN);
-        ak4396_write(chip, AK4396_CONTROL_2, data->ak4396_ctl2);
+        ak4396_write(chip, AK4396_CONTROL_2,
+                     data->ak4396_regs[AK4396_CONTROL_2]);
         ak4396_write(chip, AK4396_CONTROL_3, AK4396_PCM);
-        update_ak4396_volume(chip);
+        ak4396_write(chip, AK4396_LCH_ATT, chip->dac_volume[0]);
+        ak4396_write(chip, AK4396_RCH_ATT, chip->dac_volume[1]);
 }
 
 static void hifier_init(struct oxygen *chip)
 {
         struct hifier_data *data = chip->model_data;
 
-        data->ak4396_ctl2 = AK4396_SMUTE | AK4396_DEM_OFF | AK4396_DFS_NORMAL;
+        data->ak4396_regs[AK4396_CONTROL_2] =
+                AK4396_SMUTE | AK4396_DEM_OFF | AK4396_DFS_NORMAL;
         hifier_registers_init(chip);
 
         snd_component_add(chip->card, "AK4396");
@@ -112,20 +120,29 @@ static void set_ak4396_params(struct oxygen *chip,
         struct hifier_data *data = chip->model_data;
         u8 value;
 
-        value = data->ak4396_ctl2 & ~AK4396_DFS_MASK;
+        value = data->ak4396_regs[AK4396_CONTROL_2] & ~AK4396_DFS_MASK;
         if (params_rate(params) <= 54000)
                 value |= AK4396_DFS_NORMAL;
         else if (params_rate(params) <= 108000)
                 value |= AK4396_DFS_DOUBLE;
         else
                 value |= AK4396_DFS_QUAD;
-        data->ak4396_ctl2 = value;
 
         msleep(1); /* wait for the new MCLK to become stable */
 
-        ak4396_write(chip, AK4396_CONTROL_1, AK4396_DIF_24_MSB);
-        ak4396_write(chip, AK4396_CONTROL_2, value);
-        ak4396_write(chip, AK4396_CONTROL_1, AK4396_DIF_24_MSB | AK4396_RSTN);
+        if (value != data->ak4396_regs[AK4396_CONTROL_2]) {
+                ak4396_write(chip, AK4396_CONTROL_1,
+                             AK4396_DIF_24_MSB);
+                ak4396_write(chip, AK4396_CONTROL_2, value);
+                ak4396_write(chip, AK4396_CONTROL_1,
+                             AK4396_DIF_24_MSB | AK4396_RSTN);
+        }
+}
+
+static void update_ak4396_volume(struct oxygen *chip)
+{
+        ak4396_write_cached(chip, AK4396_LCH_ATT, chip->dac_volume[0]);
+        ak4396_write_cached(chip, AK4396_RCH_ATT, chip->dac_volume[1]);
 }
 
 static void update_ak4396_mute(struct oxygen *chip)
@@ -133,11 +150,10 @@ static void update_ak4396_mute(struct oxygen *chip)
         struct hifier_data *data = chip->model_data;
         u8 value;
 
-        value = data->ak4396_ctl2 & ~AK4396_SMUTE;
+        value = data->ak4396_regs[AK4396_CONTROL_2] & ~AK4396_SMUTE;
         if (chip->dac_mute)
                 value |= AK4396_SMUTE;
-        data->ak4396_ctl2 = value;
-        ak4396_write(chip, AK4396_CONTROL_2, value);
+        ak4396_write_cached(chip, AK4396_CONTROL_2, value);
 }
 
 static void set_cs5340_params(struct oxygen *chip,
diff --git a/sound/pci/oxygen/oxygen.c b/sound/pci/oxygen/oxygen.c
index 53dff7193f31..c986c5ebf65b 100644
--- a/sound/pci/oxygen/oxygen.c
+++ b/sound/pci/oxygen/oxygen.c
@@ -97,8 +97,8 @@ MODULE_DEVICE_TABLE(pci, oxygen_ids);
 #define GPIO_CLARO_HP           0x0100
 
 struct generic_data {
-        u8 ak4396_ctl2;
-        u16 saved_wm8785_registers[2];
+        u8 ak4396_regs[4][5];
+        u16 wm8785_regs[1];
 };
 
 static void ak4396_write(struct oxygen *chip, unsigned int codec,
@@ -108,12 +108,24 @@ static void ak4396_write(struct oxygen *chip, unsigned int codec,
         static const u8 codec_spi_map[4] = {
                 0, 1, 2, 4
         };
+        struct generic_data *data = chip->model_data;
+
         oxygen_write_spi(chip, OXYGEN_SPI_TRIGGER |
                          OXYGEN_SPI_DATA_LENGTH_2 |
                          OXYGEN_SPI_CLOCK_160 |
                          (codec_spi_map[codec] << OXYGEN_SPI_CODEC_SHIFT) |
                          OXYGEN_SPI_CEN_LATCH_CLOCK_HI,
                          AK4396_WRITE | (reg << 8) | value);
+        data->ak4396_regs[codec][reg] = value;
+}
+
+static void ak4396_write_cached(struct oxygen *chip, unsigned int codec,
+                                u8 reg, u8 value)
+{
+        struct generic_data *data = chip->model_data;
+
+        if (value != data->ak4396_regs[codec][reg])
+                ak4396_write(chip, codec, reg, value);
 }
 
 static void wm8785_write(struct oxygen *chip, u8 reg, unsigned int value)
@@ -126,20 +138,8 @@ static void wm8785_write(struct oxygen *chip, u8 reg, unsigned int value)
                          (3 << OXYGEN_SPI_CODEC_SHIFT) |
                          OXYGEN_SPI_CEN_LATCH_CLOCK_LO,
                          (reg << 9) | value);
-        if (reg < ARRAY_SIZE(data->saved_wm8785_registers))
-                data->saved_wm8785_registers[reg] = value;
-}
-
-static void update_ak4396_volume(struct oxygen *chip)
-{
-        unsigned int i;
-
-        for (i = 0; i < 4; ++i) {
-                ak4396_write(chip, i,
-                             AK4396_LCH_ATT, chip->dac_volume[i * 2]);
-                ak4396_write(chip, i,
-                             AK4396_RCH_ATT, chip->dac_volume[i * 2 + 1]);
-        }
+        if (reg < ARRAY_SIZE(data->wm8785_regs))
+                data->wm8785_regs[reg] = value;
 }
 
 static void ak4396_registers_init(struct oxygen *chip)
@@ -148,21 +148,25 @@ static void ak4396_registers_init(struct oxygen *chip)
         unsigned int i;
 
         for (i = 0; i < 4; ++i) {
-                ak4396_write(chip, i,
-                             AK4396_CONTROL_1, AK4396_DIF_24_MSB | AK4396_RSTN);
-                ak4396_write(chip, i,
-                             AK4396_CONTROL_2, data->ak4396_ctl2);
-                ak4396_write(chip, i,
-                             AK4396_CONTROL_3, AK4396_PCM);
+                ak4396_write(chip, i, AK4396_CONTROL_1,
+                             AK4396_DIF_24_MSB | AK4396_RSTN);
+                ak4396_write(chip, i, AK4396_CONTROL_2,
+                             data->ak4396_regs[0][AK4396_CONTROL_2]);
+                ak4396_write(chip, i, AK4396_CONTROL_3,
+                             AK4396_PCM);
+                ak4396_write(chip, i, AK4396_LCH_ATT,
+                             chip->dac_volume[i * 2]);
+                ak4396_write(chip, i, AK4396_RCH_ATT,
+                             chip->dac_volume[i * 2 + 1]);
         }
-        update_ak4396_volume(chip);
 }
 
 static void ak4396_init(struct oxygen *chip)
 {
         struct generic_data *data = chip->model_data;
 
-        data->ak4396_ctl2 = AK4396_SMUTE | AK4396_DEM_OFF | AK4396_DFS_NORMAL;
+        data->ak4396_regs[0][AK4396_CONTROL_2] =
+                AK4396_SMUTE | AK4396_DEM_OFF | AK4396_DFS_NORMAL;
         ak4396_registers_init(chip);
         snd_component_add(chip->card, "AK4396");
 }
@@ -179,17 +183,15 @@ static void wm8785_registers_init(struct oxygen *chip)
         struct generic_data *data = chip->model_data;
 
         wm8785_write(chip, WM8785_R7, 0);
-        wm8785_write(chip, WM8785_R0, data->saved_wm8785_registers[0]);
-        wm8785_write(chip, WM8785_R1, data->saved_wm8785_registers[1]);
+        wm8785_write(chip, WM8785_R0, data->wm8785_regs[0]);
 }
 
 static void wm8785_init(struct oxygen *chip)
 {
         struct generic_data *data = chip->model_data;
 
-        data->saved_wm8785_registers[0] = WM8785_MCR_SLAVE |
-                WM8785_OSR_SINGLE | WM8785_FORMAT_LJUST;
-        data->saved_wm8785_registers[1] = WM8785_WL_24;
+        data->wm8785_regs[0] =
+                WM8785_MCR_SLAVE | WM8785_OSR_SINGLE | WM8785_FORMAT_LJUST;
         wm8785_registers_init(chip);
         snd_component_add(chip->card, "WM8785");
 }
@@ -270,24 +272,36 @@ static void set_ak4396_params(struct oxygen *chip,
         unsigned int i;
         u8 value;
 
-        value = data->ak4396_ctl2 & ~AK4396_DFS_MASK;
+        value = data->ak4396_regs[0][AK4396_CONTROL_2] & ~AK4396_DFS_MASK;
         if (params_rate(params) <= 54000)
                 value |= AK4396_DFS_NORMAL;
         else if (params_rate(params) <= 108000)
                 value |= AK4396_DFS_DOUBLE;
         else
                 value |= AK4396_DFS_QUAD;
-        data->ak4396_ctl2 = value;
 
         msleep(1); /* wait for the new MCLK to become stable */
 
+        if (value != data->ak4396_regs[0][AK4396_CONTROL_2]) {
+                for (i = 0; i < 4; ++i) {
+                        ak4396_write(chip, i, AK4396_CONTROL_1,
+                                     AK4396_DIF_24_MSB);
+                        ak4396_write(chip, i, AK4396_CONTROL_2, value);
+                        ak4396_write(chip, i, AK4396_CONTROL_1,
+                                     AK4396_DIF_24_MSB | AK4396_RSTN);
+                }
+        }
+}
+
+static void update_ak4396_volume(struct oxygen *chip)
+{
+        unsigned int i;
+
         for (i = 0; i < 4; ++i) {
-                ak4396_write(chip, i,
-                             AK4396_CONTROL_1, AK4396_DIF_24_MSB);
-                ak4396_write(chip, i,
-                             AK4396_CONTROL_2, value);
-                ak4396_write(chip, i,
-                             AK4396_CONTROL_1, AK4396_DIF_24_MSB | AK4396_RSTN);
+                ak4396_write_cached(chip, i, AK4396_LCH_ATT,
+                                    chip->dac_volume[i * 2]);
+                ak4396_write_cached(chip, i, AK4396_RCH_ATT,
+                                    chip->dac_volume[i * 2 + 1]);
         }
 }
 
@@ -297,21 +311,19 @@ static void update_ak4396_mute(struct oxygen *chip)
         unsigned int i;
         u8 value;
 
-        value = data->ak4396_ctl2 & ~AK4396_SMUTE;
+        value = data->ak4396_regs[0][AK4396_CONTROL_2] & ~AK4396_SMUTE;
         if (chip->dac_mute)
                 value |= AK4396_SMUTE;
-        data->ak4396_ctl2 = value;
         for (i = 0; i < 4; ++i)
-                ak4396_write(chip, i, AK4396_CONTROL_2, value);
+                ak4396_write_cached(chip, i, AK4396_CONTROL_2, value);
 }
 
 static void set_wm8785_params(struct oxygen *chip,
                               struct snd_pcm_hw_params *params)
 {
+        struct generic_data *data = chip->model_data;
         unsigned int value;
 
-        wm8785_write(chip, WM8785_R7, 0);
-
         value = WM8785_MCR_SLAVE | WM8785_FORMAT_LJUST;
         if (params_rate(params) <= 48000)
                 value |= WM8785_OSR_SINGLE;
@@ -319,13 +331,10 @@ static void set_wm8785_params(struct oxygen *chip,
                 value |= WM8785_OSR_DOUBLE;
         else
                 value |= WM8785_OSR_QUAD;
-        wm8785_write(chip, WM8785_R0, value);
-
-        if (snd_pcm_format_width(params_format(params)) <= 16)
-                value = WM8785_WL_16;
-        else
-                value = WM8785_WL_24;
-        wm8785_write(chip, WM8785_R1, value);
+        if (value != data->wm8785_regs[0]) {
+                wm8785_write(chip, WM8785_R7, 0);
+                wm8785_write(chip, WM8785_R0, value);
+        }
 }
 
 static void set_ak5385_params(struct oxygen *chip,
diff --git a/sound/pci/oxygen/xonar_cs43xx.c b/sound/pci/oxygen/xonar_cs43xx.c
index a8ec4e8271a4..330c5e755917 100644
--- a/sound/pci/oxygen/xonar_cs43xx.c
+++ b/sound/pci/oxygen/xonar_cs43xx.c
@@ -69,62 +69,58 @@
 
 struct xonar_cs43xx {
         struct xonar_generic generic;
-        u8 cs4398_fm;
-        u8 cs4362a_fm;
-        u8 cs4362a_fm_c;
+        u8 cs4398_regs[7];
+        u8 cs4362a_regs[15];
 };
 
 static void cs4398_write(struct oxygen *chip, u8 reg, u8 value)
 {
-        oxygen_write_i2c(chip, I2C_DEVICE_CS4398, reg, value);
-}
+        struct xonar_cs43xx *data = chip->model_data;
 
-static void cs4362a_write(struct oxygen *chip, u8 reg, u8 value)
-{
-        oxygen_write_i2c(chip, I2C_DEVICE_CS4362A, reg, value);
+        oxygen_write_i2c(chip, I2C_DEVICE_CS4398, reg, value);
+        if (reg < ARRAY_SIZE(data->cs4398_regs))
+                data->cs4398_regs[reg] = value;
 }
 
-static void update_cs4362a_volumes(struct oxygen *chip)
+static void cs4398_write_cached(struct oxygen *chip, u8 reg, u8 value)
 {
-        u8 mute;
+        struct xonar_cs43xx *data = chip->model_data;
 
-        mute = chip->dac_mute ? CS4362A_MUTE : 0;
-        cs4362a_write(chip, 7, (127 - chip->dac_volume[2]) | mute);
-        cs4362a_write(chip, 8, (127 - chip->dac_volume[3]) | mute);
-        cs4362a_write(chip, 10, (127 - chip->dac_volume[4]) | mute);
-        cs4362a_write(chip, 11, (127 - chip->dac_volume[5]) | mute);
-        cs4362a_write(chip, 13, (127 - chip->dac_volume[6]) | mute);
-        cs4362a_write(chip, 14, (127 - chip->dac_volume[7]) | mute);
+        if (value != data->cs4398_regs[reg])
+                cs4398_write(chip, reg, value);
 }
 
-static void update_cs43xx_volume(struct oxygen *chip)
+static void cs4362a_write(struct oxygen *chip, u8 reg, u8 value)
 {
-        cs4398_write(chip, 5, (127 - chip->dac_volume[0]) * 2);
-        cs4398_write(chip, 6, (127 - chip->dac_volume[1]) * 2);
-        update_cs4362a_volumes(chip);
+        struct xonar_cs43xx *data = chip->model_data;
+
+        oxygen_write_i2c(chip, I2C_DEVICE_CS4362A, reg, value);
+        if (reg < ARRAY_SIZE(data->cs4362a_regs))
+                data->cs4362a_regs[reg] = value;
 }
 
-static void update_cs43xx_mute(struct oxygen *chip)
+static void cs4362a_write_cached(struct oxygen *chip, u8 reg, u8 value)
 {
-        u8 reg;
+        struct xonar_cs43xx *data = chip->model_data;
 
-        reg = CS4398_MUTEP_LOW | CS4398_PAMUTE;
-        if (chip->dac_mute)
-                reg |= CS4398_MUTE_B | CS4398_MUTE_A;
-        cs4398_write(chip, 4, reg);
-        update_cs4362a_volumes(chip);
+        if (value != data->cs4362a_regs[reg])
+                cs4362a_write(chip, reg, value);
 }
 
-static void cs43xx_init(struct oxygen *chip)
+static void cs43xx_registers_init(struct oxygen *chip)
 {
         struct xonar_cs43xx *data = chip->model_data;
+        unsigned int i;
 
         /* set CPEN (control port mode) and power down */
         cs4398_write(chip, 8, CS4398_CPEN | CS4398_PDN);
         cs4362a_write(chip, 0x01, CS4362A_PDN | CS4362A_CPEN);
         /* configure */
-        cs4398_write(chip, 2, data->cs4398_fm);
+        cs4398_write(chip, 2, data->cs4398_regs[2]);
         cs4398_write(chip, 3, CS4398_ATAPI_B_R | CS4398_ATAPI_A_L);
+        cs4398_write(chip, 4, data->cs4398_regs[4]);
+        cs4398_write(chip, 5, data->cs4398_regs[5]);
+        cs4398_write(chip, 6, data->cs4398_regs[6]);
         cs4398_write(chip, 7, CS4398_RMP_DN | CS4398_RMP_UP |
                      CS4398_ZERO_CROSS | CS4398_SOFT_RAMP);
         cs4362a_write(chip, 0x02, CS4362A_DIF_LJUST);
@@ -132,11 +128,8 @@ static void cs43xx_init(struct oxygen *chip)
                       CS4362A_RMP_UP | CS4362A_ZERO_CROSS | CS4362A_SOFT_RAMP);
         cs4362a_write(chip, 0x04, CS4362A_RMP_DN | CS4362A_DEM_NONE);
         cs4362a_write(chip, 0x05, 0);
-        cs4362a_write(chip, 0x06, data->cs4362a_fm);
-        cs4362a_write(chip, 0x09, data->cs4362a_fm_c);
-        cs4362a_write(chip, 0x0c, data->cs4362a_fm);
-        update_cs43xx_volume(chip);
-        update_cs43xx_mute(chip);
+        for (i = 6; i <= 14; ++i)
+                cs4362a_write(chip, i, data->cs4362a_regs[i]);
         /* clear power down */
         cs4398_write(chip, 8, CS4398_CPEN);
         cs4362a_write(chip, 0x01, CS4362A_CPEN);
@@ -148,17 +141,29 @@ static void xonar_d1_init(struct oxygen *chip)
 
         data->generic.anti_pop_delay = 800;
         data->generic.output_enable_bit = GPIO_D1_OUTPUT_ENABLE;
-        data->cs4398_fm = CS4398_FM_SINGLE | CS4398_DEM_NONE | CS4398_DIF_LJUST;
-        data->cs4362a_fm = CS4362A_FM_SINGLE |
+        data->cs4398_regs[2] =
+                CS4398_FM_SINGLE | CS4398_DEM_NONE | CS4398_DIF_LJUST;
+        data->cs4398_regs[4] = CS4398_MUTEP_LOW |
+                CS4398_MUTE_B | CS4398_MUTE_A | CS4398_PAMUTE;
+        data->cs4398_regs[5] = 60 * 2;
+        data->cs4398_regs[6] = 60 * 2;
+        data->cs4362a_regs[6] = CS4362A_FM_SINGLE |
                 CS4362A_ATAPI_B_R | CS4362A_ATAPI_A_L;
-        data->cs4362a_fm_c = data->cs4362a_fm;
+        data->cs4362a_regs[7] = 60 | CS4362A_MUTE;
+        data->cs4362a_regs[8] = 60 | CS4362A_MUTE;
+        data->cs4362a_regs[9] = data->cs4362a_regs[6];
+        data->cs4362a_regs[10] = 60 | CS4362A_MUTE;
+        data->cs4362a_regs[11] = 60 | CS4362A_MUTE;
+        data->cs4362a_regs[12] = data->cs4362a_regs[6];
+        data->cs4362a_regs[13] = 60 | CS4362A_MUTE;
+        data->cs4362a_regs[14] = 60 | CS4362A_MUTE;
 
         oxygen_write16(chip, OXYGEN_2WIRE_BUS_STATUS,
                        OXYGEN_2WIRE_LENGTH_8 |
                        OXYGEN_2WIRE_INTERRUPT_MASK |
                        OXYGEN_2WIRE_SPEED_FAST);
 
-        cs43xx_init(chip);
+        cs43xx_registers_init(chip);
 
         oxygen_set_bits16(chip, OXYGEN_GPIO_CONTROL,
                           GPIO_D1_FRONT_PANEL | GPIO_D1_INPUT_ROUTE);
@@ -200,7 +205,7 @@ static void xonar_d1_resume(struct oxygen *chip)
 {
         oxygen_set_bits8(chip, OXYGEN_FUNCTION, OXYGEN_FUNCTION_RESET_CODEC);
         msleep(1);
-        cs43xx_init(chip);
+        cs43xx_registers_init(chip);
         xonar_enable_output(chip);
 }
 
@@ -220,27 +225,56 @@ static void set_cs43xx_params(struct oxygen *chip,
                 cs4398_fm = CS4398_FM_QUAD;
                 cs4362a_fm = CS4362A_FM_QUAD;
         }
-        data->cs4398_fm = CS4398_DEM_NONE | CS4398_DIF_LJUST | cs4398_fm;
-        data->cs4362a_fm =
-                (data->cs4362a_fm & ~CS4362A_FM_MASK) | cs4362a_fm;
-        data->cs4362a_fm_c =
-                (data->cs4362a_fm_c & ~CS4362A_FM_MASK) | cs4362a_fm;
-        cs4398_write(chip, 2, data->cs4398_fm);
-        cs4362a_write(chip, 0x06, data->cs4362a_fm);
-        cs4362a_write(chip, 0x09, data->cs4362a_fm_c);
-        cs4362a_write(chip, 0x0c, data->cs4362a_fm);
+        cs4398_fm |= CS4398_DEM_NONE | CS4398_DIF_LJUST;
+        cs4398_write_cached(chip, 2, cs4398_fm);
+        cs4362a_fm |= data->cs4362a_regs[6] & ~CS4362A_FM_MASK;
+        cs4362a_write_cached(chip, 6, cs4362a_fm);
+        cs4362a_write_cached(chip, 12, cs4362a_fm);
+        cs4362a_fm &= CS4362A_FM_MASK;
+        cs4362a_fm |= data->cs4362a_regs[9] & ~CS4362A_FM_MASK;
+        cs4362a_write_cached(chip, 9, cs4362a_fm);
+}
+
+static void update_cs4362a_volumes(struct oxygen *chip)
+{
+        unsigned int i;
+        u8 mute;
+
+        mute = chip->dac_mute ? CS4362A_MUTE : 0;
+        for (i = 0; i < 6; ++i)
+                cs4362a_write_cached(chip, 7 + i + i / 2,
+                                     (127 - chip->dac_volume[2 + i]) | mute);
+}
+
+static void update_cs43xx_volume(struct oxygen *chip)
+{
+        cs4398_write_cached(chip, 5, (127 - chip->dac_volume[0]) * 2);
+        cs4398_write_cached(chip, 6, (127 - chip->dac_volume[1]) * 2);
+        update_cs4362a_volumes(chip);
+}
+
+static void update_cs43xx_mute(struct oxygen *chip)
+{
+        u8 reg;
+
+        reg = CS4398_MUTEP_LOW | CS4398_PAMUTE;
+        if (chip->dac_mute)
+                reg |= CS4398_MUTE_B | CS4398_MUTE_A;
+        cs4398_write_cached(chip, 4, reg);
+        update_cs4362a_volumes(chip);
 }
 
 static void update_cs43xx_center_lfe_mix(struct oxygen *chip, bool mixed)
 {
         struct xonar_cs43xx *data = chip->model_data;
+        u8 reg;
 
-        data->cs4362a_fm_c &= ~CS4362A_ATAPI_MASK;
+        reg = data->cs4362a_regs[9] & ~CS4362A_ATAPI_MASK;
         if (mixed)
-                data->cs4362a_fm_c |= CS4362A_ATAPI_B_LR | CS4362A_ATAPI_A_LR;
+                reg |= CS4362A_ATAPI_B_LR | CS4362A_ATAPI_A_LR;
         else
-                data->cs4362a_fm_c |= CS4362A_ATAPI_B_R | CS4362A_ATAPI_A_L;
-        cs4362a_write(chip, 0x09, data->cs4362a_fm_c);
+                reg |= CS4362A_ATAPI_B_R | CS4362A_ATAPI_A_L;
+        cs4362a_write_cached(chip, 9, reg);
 }
 
 static const struct snd_kcontrol_new front_panel_switch = {
diff --git a/sound/pci/oxygen/xonar_pcm179x.c b/sound/pci/oxygen/xonar_pcm179x.c
index 97574dbec2b6..e17ee5e8e510 100644
--- a/sound/pci/oxygen/xonar_pcm179x.c
+++ b/sound/pci/oxygen/xonar_pcm179x.c
@@ -166,11 +166,13 @@
 #define I2C_DEVICE_PCM1796(i)   (0x98 + ((i) << 1))     /* 10011, ii, /W=0 */
 #define I2C_DEVICE_CS2000       0x9c                    /* 100111, 0, /W=0 */
 
+#define PCM1796_REG_BASE        16
+
 
 struct xonar_pcm179x {
         struct xonar_generic generic;
         unsigned int dacs;
-        u8 oversampling;
+        u8 pcm1796_regs[4][5];
         u8 cs2000_fun_cfg_1;
 };
 
@@ -204,54 +206,71 @@ static inline void pcm1796_write_i2c(struct oxygen *chip, unsigned int codec,
 static void pcm1796_write(struct oxygen *chip, unsigned int codec,
                           u8 reg, u8 value)
 {
+        struct xonar_pcm179x *data = chip->model_data;
+
         if ((chip->model.function_flags & OXYGEN_FUNCTION_2WIRE_SPI_MASK) ==
             OXYGEN_FUNCTION_SPI)
                 pcm1796_write_spi(chip, codec, reg, value);
         else
                 pcm1796_write_i2c(chip, codec, reg, value);
+        if ((unsigned int)(reg - PCM1796_REG_BASE)
+            < ARRAY_SIZE(data->pcm1796_regs[codec]))
+                data->pcm1796_regs[codec][reg - PCM1796_REG_BASE] = value;
 }
 
-static void cs2000_write(struct oxygen *chip, u8 reg, u8 value)
+static void pcm1796_write_cached(struct oxygen *chip, unsigned int codec,
+                                 u8 reg, u8 value)
 {
-        oxygen_write_i2c(chip, I2C_DEVICE_CS2000, reg, value);
+        struct xonar_pcm179x *data = chip->model_data;
+
+        if (value != data->pcm1796_regs[codec][reg - PCM1796_REG_BASE])
+                pcm1796_write(chip, codec, reg, value);
 }
 
-static void update_pcm1796_volume(struct oxygen *chip)
+static void cs2000_write(struct oxygen *chip, u8 reg, u8 value)
 {
         struct xonar_pcm179x *data = chip->model_data;
-        unsigned int i;
 
-        for (i = 0; i < data->dacs; ++i) {
-                pcm1796_write(chip, i, 16, chip->dac_volume[i * 2]);
-                pcm1796_write(chip, i, 17, chip->dac_volume[i * 2 + 1]);
-        }
+        oxygen_write_i2c(chip, I2C_DEVICE_CS2000, reg, value);
+        if (reg == CS2000_FUN_CFG_1)
+                data->cs2000_fun_cfg_1 = value;
 }
 
-static void update_pcm1796_mute(struct oxygen *chip)
+static void cs2000_write_cached(struct oxygen *chip, u8 reg, u8 value)
 {
         struct xonar_pcm179x *data = chip->model_data;
-        unsigned int i;
-        u8 value;
 
-        value = PCM1796_DMF_DISABLED | PCM1796_FMT_24_LJUST | PCM1796_ATLD;
-        if (chip->dac_mute)
-                value |= PCM1796_MUTE;
-        for (i = 0; i < data->dacs; ++i)
-                pcm1796_write(chip, i, 18, value);
+        if (reg != CS2000_FUN_CFG_1 ||
+            value != data->cs2000_fun_cfg_1)
+                cs2000_write(chip, reg, value);
 }
 
-static void pcm1796_init(struct oxygen *chip)
+static void pcm1796_registers_init(struct oxygen *chip)
 {
         struct xonar_pcm179x *data = chip->model_data;
         unsigned int i;
 
         for (i = 0; i < data->dacs; ++i) {
+                /* set ATLD before ATL/ATR */
+                pcm1796_write(chip, i, 18,
+                              data->pcm1796_regs[0][18 - PCM1796_REG_BASE]);
+                pcm1796_write(chip, i, 16, chip->dac_volume[i * 2]);
+                pcm1796_write(chip, i, 17, chip->dac_volume[i * 2 + 1]);
                 pcm1796_write(chip, i, 19, PCM1796_FLT_SHARP | PCM1796_ATS_1);
-                pcm1796_write(chip, i, 20, data->oversampling);
+                pcm1796_write(chip, i, 20,
+                              data->pcm1796_regs[0][20 - PCM1796_REG_BASE]);
                 pcm1796_write(chip, i, 21, 0);
         }
-        update_pcm1796_mute(chip); /* set ATLD before ATL/ATR */
-        update_pcm1796_volume(chip);
+}
+
+static void pcm1796_init(struct oxygen *chip)
+{
+        struct xonar_pcm179x *data = chip->model_data;
+
+        data->pcm1796_regs[0][18 - PCM1796_REG_BASE] = PCM1796_MUTE |
+                PCM1796_DMF_DISABLED | PCM1796_FMT_24_LJUST | PCM1796_ATLD;
+        data->pcm1796_regs[0][20 - PCM1796_REG_BASE] = PCM1796_OS_64;
+        pcm1796_registers_init(chip);
 }
 
 static void xonar_d2_init(struct oxygen *chip)
@@ -261,7 +280,6 @@ static void xonar_d2_init(struct oxygen *chip)
         data->generic.anti_pop_delay = 300;
         data->generic.output_enable_bit = GPIO_D2_OUTPUT_ENABLE;
         data->dacs = 4;
-        data->oversampling = PCM1796_OS_64;
 
         pcm1796_init(chip);
 
@@ -304,7 +322,6 @@ static void xonar_hdav_init(struct oxygen *chip)
         data->pcm179x.generic.ext_power_int_reg = OXYGEN_GPI_INTERRUPT_MASK;
         data->pcm179x.generic.ext_power_bit = GPI_EXT_POWER;
         data->pcm179x.dacs = chip->model.private_data ? 4 : 1;
-        data->pcm179x.oversampling = PCM1796_OS_64;
 
         pcm1796_init(chip);
 
@@ -335,7 +352,6 @@ static void xonar_st_init_common(struct oxygen *chip)
         data->generic.anti_pop_delay = 100;
         data->generic.output_enable_bit = GPIO_ST_OUTPUT_ENABLE;
         data->dacs = chip->model.private_data ? 4 : 1;
-        data->oversampling = PCM1796_OS_64;
 
         pcm1796_init(chip);
 
@@ -438,7 +454,7 @@ static void xonar_st_suspend(struct oxygen *chip)
 
 static void xonar_d2_resume(struct oxygen *chip)
 {
-        pcm1796_init(chip);
+        pcm1796_registers_init(chip);
         xonar_enable_output(chip);
 }
 
@@ -446,14 +462,14 @@ static void xonar_hdav_resume(struct oxygen *chip)
 {
         struct xonar_hdav *data = chip->model_data;
 
-        pcm1796_init(chip);
+        pcm1796_registers_init(chip);
         xonar_hdmi_resume(chip, &data->hdmi);
         xonar_enable_output(chip);
 }
 
 static void xonar_stx_resume(struct oxygen *chip)
 {
-        pcm1796_init(chip);
+        pcm1796_registers_init(chip);
         xonar_enable_output(chip);
 }
 
@@ -468,11 +484,35 @@ static void set_pcm1796_params(struct oxygen *chip,
 {
         struct xonar_pcm179x *data = chip->model_data;
         unsigned int i;
+        u8 reg;
+
+        reg = params_rate(params) >= 96000 ? PCM1796_OS_32 : PCM1796_OS_64;
+        for (i = 0; i < data->dacs; ++i)
+                pcm1796_write_cached(chip, i, 20, reg);
+}
+
+static void update_pcm1796_volume(struct oxygen *chip)
+{
+        struct xonar_pcm179x *data = chip->model_data;
+        unsigned int i;
+
+        for (i = 0; i < data->dacs; ++i) {
+                pcm1796_write_cached(chip, i, 16, chip->dac_volume[i * 2]);
+                pcm1796_write_cached(chip, i, 17, chip->dac_volume[i * 2 + 1]);
+        }
+}
+
+static void update_pcm1796_mute(struct oxygen *chip)
+{
+        struct xonar_pcm179x *data = chip->model_data;
+        unsigned int i;
+        u8 value;
 
-        data->oversampling =
-                params_rate(params) >= 96000 ? PCM1796_OS_32 : PCM1796_OS_64;
+        value = PCM1796_DMF_DISABLED | PCM1796_FMT_24_LJUST | PCM1796_ATLD;
+        if (chip->dac_mute)
+                value |= PCM1796_MUTE;
         for (i = 0; i < data->dacs; ++i)
-                pcm1796_write(chip, i, 20, data->oversampling);
+                pcm1796_write_cached(chip, i, 18, value);
 }
 
 static void set_cs2000_params(struct oxygen *chip,
@@ -489,9 +529,8 @@ static void set_cs2000_params(struct oxygen *chip,
                 [OXYGEN_RATE_176400] = OXYGEN_RATE_44100 | OXYGEN_I2S_MCLK_256,
                 [OXYGEN_RATE_192000] = OXYGEN_RATE_48000 | OXYGEN_I2S_MCLK_256,
         };
-        struct xonar_pcm179x *data = chip->model_data;
         unsigned int rate_index;
-        u8 rate_mclk;
+        u8 rate_mclk, reg;
 
         rate_index = oxygen_read16(chip, OXYGEN_I2S_MULTICH_FORMAT)
                 & OXYGEN_I2S_RATE_MASK;
@@ -499,10 +538,10 @@ static void set_cs2000_params(struct oxygen *chip,
         oxygen_write16_masked(chip, OXYGEN_I2S_A_FORMAT, rate_mclk,
                               OXYGEN_I2S_RATE_MASK | OXYGEN_I2S_MCLK_MASK);
         if ((rate_mclk & OXYGEN_I2S_MCLK_MASK) <= OXYGEN_I2S_MCLK_128)
-                data->cs2000_fun_cfg_1 = CS2000_REF_CLK_DIV_1;
+                reg = CS2000_REF_CLK_DIV_1;
         else
-                data->cs2000_fun_cfg_1 = CS2000_REF_CLK_DIV_2;
-        cs2000_write(chip, CS2000_FUN_CFG_1, data->cs2000_fun_cfg_1);
+                reg = CS2000_REF_CLK_DIV_2;
+        cs2000_write_cached(chip, CS2000_FUN_CFG_1, reg);
 }
 
 static void set_st_params(struct oxygen *chip,