Staging: Lindent the echo driver

Lindent drivers/staging/echo*

Signed-off by: J.R. Mauro <jrm8005@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

6 files changed, 654 insertions, 672 deletions

diff --git a/drivers/staging/echo/bit_operations.h b/drivers/staging/echo/bit_operations.h
index abcd7a2168a..cecdcf3fd75 100644
--- a/drivers/staging/echo/bit_operations.h
+++ b/drivers/staging/echo/bit_operations.h
@@ -36,14 +36,15 @@
     \return The bit number of the highest set bit, or -1 if the word is zero. */
 static __inline__ int top_bit(unsigned int bits)
 {
-    int res;
-
-    __asm__ (" xorl %[res],%[res];\n"
-             " decl %[res];\n"
-             " bsrl %[bits],%[res]\n"
-             : [res] "=&r" (res)
-             : [bits] "rm" (bits));
-    return res;
+	int res;
+
+	__asm__(" xorl %[res],%[res];\n"
+		" decl %[res];\n"
+		" bsrl %[bits],%[res]\n"
+		:[res] "=&r" (res)
+		:[bits] "rm"(bits)
+	);
+	return res;
 }
 
 /*! \brief Find the bit position of the lowest set bit in a word
@@ -51,84 +52,75 @@ static __inline__ int top_bit(unsigned int bits)
     \return The bit number of the lowest set bit, or -1 if the word is zero. */
 static __inline__ int bottom_bit(unsigned int bits)
 {
-    int res;
-
-    __asm__ (" xorl %[res],%[res];\n"
-             " decl %[res];\n"
-             " bsfl %[bits],%[res]\n"
-             : [res] "=&r" (res)
-             : [bits] "rm" (bits));
-    return res;
+	int res;
+
+	__asm__(" xorl %[res],%[res];\n"
+		" decl %[res];\n"
+		" bsfl %[bits],%[res]\n"
+		:[res] "=&r" (res)
+		:[bits] "rm"(bits)
+	);
+	return res;
 }
 #else
 static __inline__ int top_bit(unsigned int bits)
 {
-    int i;
-
-    if (bits == 0)
-        return -1;
-    i = 0;
-    if (bits & 0xFFFF0000)
-    {
-        bits &= 0xFFFF0000;
-        i += 16;
-    }
-    if (bits & 0xFF00FF00)
-    {
-        bits &= 0xFF00FF00;
-        i += 8;
-    }
-    if (bits & 0xF0F0F0F0)
-    {
-        bits &= 0xF0F0F0F0;
-        i += 4;
-    }
-    if (bits & 0xCCCCCCCC)
-    {
-        bits &= 0xCCCCCCCC;
-        i += 2;
-    }
-    if (bits & 0xAAAAAAAA)
-    {
-        bits &= 0xAAAAAAAA;
-        i += 1;
-    }
-    return i;
+	int i;
+
+	if (bits == 0)
+		return -1;
+	i = 0;
+	if (bits & 0xFFFF0000) {
+		bits &= 0xFFFF0000;
+		i += 16;
+	}
+	if (bits & 0xFF00FF00) {
+		bits &= 0xFF00FF00;
+		i += 8;
+	}
+	if (bits & 0xF0F0F0F0) {
+		bits &= 0xF0F0F0F0;
+		i += 4;
+	}
+	if (bits & 0xCCCCCCCC) {
+		bits &= 0xCCCCCCCC;
+		i += 2;
+	}
+	if (bits & 0xAAAAAAAA) {
+		bits &= 0xAAAAAAAA;
+		i += 1;
+	}
+	return i;
 }
 
 static __inline__ int bottom_bit(unsigned int bits)
 {
-    int i;
-
-    if (bits == 0)
-        return -1;
-    i = 32;
-    if (bits & 0x0000FFFF)
-    {
-        bits &= 0x0000FFFF;
-        i -= 16;
-    }
-    if (bits & 0x00FF00FF)
-    {
-        bits &= 0x00FF00FF;
-        i -= 8;
-    }
-    if (bits & 0x0F0F0F0F)
-    {
-        bits &= 0x0F0F0F0F;
-        i -= 4;
-    }
-    if (bits & 0x33333333)
-    {
-        bits &= 0x33333333;
-        i -= 2;
-    }
-    if (bits & 0x55555555)
-    {
-        bits &= 0x55555555;
-        i -= 1;
-    }
-    return i;
+	int i;
+
+	if (bits == 0)
+		return -1;
+	i = 32;
+	if (bits & 0x0000FFFF) {
+		bits &= 0x0000FFFF;
+		i -= 16;
+	}
+	if (bits & 0x00FF00FF) {
+		bits &= 0x00FF00FF;
+		i -= 8;
+	}
+	if (bits & 0x0F0F0F0F) {
+		bits &= 0x0F0F0F0F;
+		i -= 4;
+	}
+	if (bits & 0x33333333) {
+		bits &= 0x33333333;
+		i -= 2;
+	}
+	if (bits & 0x55555555) {
+		bits &= 0x55555555;
+		i -= 1;
+	}
+	return i;
 }
 #endif
 
@@ -138,13 +130,14 @@ static __inline__ int bottom_bit(unsigned int bits)
 static __inline__ uint8_t bit_reverse8(uint8_t x)
 {
 #if defined(__i386__)  ||  defined(__x86_64__)
-    /* If multiply is fast */
-    return ((x*0x0802U & 0x22110U) | (x*0x8020U & 0x88440U))*0x10101U >> 16;
+	/* If multiply is fast */
+	return ((x * 0x0802U & 0x22110U) | (x * 0x8020U & 0x88440U)) *
+	    0x10101U >> 16;
 #else
-    /* If multiply is slow, but we have a barrel shifter */
-    x = (x >> 4) | (x << 4);
-    x = ((x & 0xCC) >> 2) | ((x & 0x33) << 2);
-    return ((x & 0xAA) >> 1) | ((x & 0x55) << 1);
+	/* If multiply is slow, but we have a barrel shifter */
+	x = (x >> 4) | (x << 4);
+	x = ((x & 0xCC) >> 2) | ((x & 0x33) << 2);
+	return ((x & 0xAA) >> 1) | ((x & 0x55) << 1);
 #endif
 }
 
@@ -184,7 +177,7 @@ uint16_t make_mask16(uint16_t x);
     \return The word with the single set bit. */
 static __inline__ uint32_t least_significant_one32(uint32_t x)
 {
-    return (x & (-(int32_t) x));
+	return (x & (-(int32_t) x));
 }
 
 /*! \brief Find the most significant one in a word, and return a word
@@ -194,10 +187,10 @@ static __inline__ uint32_t least_significant_one32(uint32_t x)
 static __inline__ uint32_t most_significant_one32(uint32_t x)
 {
 #if defined(__i386__)  ||  defined(__x86_64__)
-    return 1 << top_bit(x);
+	return 1 << top_bit(x);
 #else
-    x = make_mask32(x);
-    return (x ^ (x >> 1));
+	x = make_mask32(x);
+	return (x ^ (x >> 1));
 #endif
 }
 
@@ -206,8 +199,8 @@ static __inline__ uint32_t most_significant_one32(uint32_t x)
     \return 1 for odd, or 0 for even. */
 static __inline__ int parity8(uint8_t x)
 {
-    x = (x ^ (x >> 4)) & 0x0F;
-    return (0x6996 >> x) & 1;
+	x = (x ^ (x >> 4)) & 0x0F;
+	return (0x6996 >> x) & 1;
 }
 
 /*! \brief Find the parity of a 16 bit word.
@@ -215,9 +208,9 @@ static __inline__ int parity8(uint8_t x)
     \return 1 for odd, or 0 for even. */
 static __inline__ int parity16(uint16_t x)
 {
-    x ^= (x >> 8);
-    x = (x ^ (x >> 4)) & 0x0F;
-    return (0x6996 >> x) & 1;
+	x ^= (x >> 8);
+	x = (x ^ (x >> 4)) & 0x0F;
+	return (0x6996 >> x) & 1;
 }
 
 /*! \brief Find the parity of a 32 bit word.
@@ -225,10 +218,10 @@ static __inline__ int parity16(uint16_t x)
     \return 1 for odd, or 0 for even. */
 static __inline__ int parity32(uint32_t x)
 {
-    x ^= (x >> 16);
-    x ^= (x >> 8);
-    x = (x ^ (x >> 4)) & 0x0F;
-    return (0x6996 >> x) & 1;
+	x ^= (x >> 16);
+	x ^= (x >> 8);
+	x = (x ^ (x >> 4)) & 0x0F;
+	return (0x6996 >> x) & 1;
 }
 
 #endif
diff --git a/drivers/staging/echo/echo.c b/drivers/staging/echo/echo.c
index ad18a959393..b8f2c5e9dee 100644
--- a/drivers/staging/echo/echo.c
+++ b/drivers/staging/echo/echo.c
@@ -74,7 +74,6 @@
 
    Steve also has some nice notes on echo cancellers in echo.h
 
-
    References:
 
    [1] Ochiai, Areseki, and Ogihara, "Echo Canceller with Two Echo
@@ -105,7 +104,7 @@
    Mark, Pawel, and Pavel.
 */
 
-#include <linux/kernel.h>       /* We're doing kernel work */
+#include <linux/kernel.h>	/* We're doing kernel work */
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
@@ -115,8 +114,8 @@
 
 #define MIN_TX_POWER_FOR_ADAPTION   64
 #define MIN_RX_POWER_FOR_ADAPTION   64
-#define DTD_HANGOVER               600     /* 600 samples, or 75ms     */
-#define DC_LOG2BETA                  3     /* log2() of DC filter Beta */
+#define DTD_HANGOVER               600	/* 600 samples, or 75ms     */
+#define DC_LOG2BETA                  3	/* log2() of DC filter Beta */
 
 /*-----------------------------------------------------------------------*\
                                FUNCTIONS
@@ -124,59 +123,58 @@
 
 /* adapting coeffs using the traditional stochastic descent (N)LMS algorithm */
 
-
 #ifdef __bfin__
-static void __inline__ lms_adapt_bg(struct oslec_state *ec, int clean, int shift)
+static void __inline__ lms_adapt_bg(struct oslec_state *ec, int clean,
+				    int shift)
 {
-    int i, j;
-    int offset1;
-    int offset2;
-    int factor;
-    int exp;
-    int16_t *phist;
-    int n;
-
-    if (shift > 0)
-	factor = clean << shift;
-    else
-	factor = clean >> -shift;
-
-    /* Update the FIR taps */
-
-    offset2 = ec->curr_pos;
-    offset1 = ec->taps - offset2;
-    phist = &ec->fir_state_bg.history[offset2];
-
-    /* st: and en: help us locate the assembler in echo.s */
-
-    //asm("st:");
-    n = ec->taps;
-    for (i = 0, j = offset2;  i < n;  i++, j++)
-    {
-       exp = *phist++ * factor;
-       ec->fir_taps16[1][i] += (int16_t) ((exp+(1<<14)) >> 15);
-    }
-    //asm("en:");
-
-    /* Note the asm for the inner loop above generated by Blackfin gcc
-       4.1.1 is pretty good (note even parallel instructions used):
-
-    	R0 = W [P0++] (X);
-	R0 *= R2;
-	R0 = R0 + R3 (NS) ||
-	R1 = W [P1] (X) ||
-	nop;
-	R0 >>>= 15;
-	R0 = R0 + R1;
-	W [P1++] = R0;
-
-	A block based update algorithm would be much faster but the
-	above can't be improved on much.  Every instruction saved in
-	the loop above is 2 MIPs/ch!  The for loop above is where the
-	Blackfin spends most of it's time - about 17 MIPs/ch measured
-	with speedtest.c with 256 taps (32ms).  Write-back and
-	Write-through cache gave about the same performance.
-    */
+	int i, j;
+	int offset1;
+	int offset2;
+	int factor;
+	int exp;
+	int16_t *phist;
+	int n;
+
+	if (shift > 0)
+		factor = clean << shift;
+	else
+		factor = clean >> -shift;
+
+	/* Update the FIR taps */
+
+	offset2 = ec->curr_pos;
+	offset1 = ec->taps - offset2;
+	phist = &ec->fir_state_bg.history[offset2];
+
+	/* st: and en: help us locate the assembler in echo.s */
+
+	//asm("st:");
+	n = ec->taps;
+	for (i = 0, j = offset2; i < n; i++, j++) {
+		exp = *phist++ * factor;
+		ec->fir_taps16[1][i] += (int16_t) ((exp + (1 << 14)) >> 15);
+	}
+	//asm("en:");
+
+	/* Note the asm for the inner loop above generated by Blackfin gcc
+	   4.1.1 is pretty good (note even parallel instructions used):
+
+	   R0 = W [P0++] (X);
+	   R0 *= R2;
+	   R0 = R0 + R3 (NS) ||
+	   R1 = W [P1] (X) ||
+	   nop;
+	   R0 >>>= 15;
+	   R0 = R0 + R1;
+	   W [P1++] = R0;
+
+	   A block based update algorithm would be much faster but the
+	   above can't be improved on much.  Every instruction saved in
+	   the loop above is 2 MIPs/ch!  The for loop above is where the
+	   Blackfin spends most of it's time - about 17 MIPs/ch measured
+	   with speedtest.c with 256 taps (32ms).  Write-back and
+	   Write-through cache gave about the same performance.
+	 */
 }
 
 /*
@@ -198,94 +196,90 @@ static void __inline__ lms_adapt_bg(struct oslec_state *ec, int clean, int shift
 */
 
 #else
-static __inline__ void lms_adapt_bg(struct oslec_state *ec, int clean, int shift)
+static __inline__ void lms_adapt_bg(struct oslec_state *ec, int clean,
+				    int shift)
 {
-    int i;
-
-    int offset1;
-    int offset2;
-    int factor;
-    int exp;
-
-    if (shift > 0)
-	factor = clean << shift;
-    else
-	factor = clean >> -shift;
-
-    /* Update the FIR taps */
-
-    offset2 = ec->curr_pos;
-    offset1 = ec->taps - offset2;
-
-    for (i = ec->taps - 1;  i >= offset1;  i--)
-    {
-       exp = (ec->fir_state_bg.history[i - offset1]*factor);
-       ec->fir_taps16[1][i] += (int16_t) ((exp+(1<<14)) >> 15);
-    }
-    for (  ;  i >= 0;  i--)
-    {
-       exp = (ec->fir_state_bg.history[i + offset2]*factor);
-       ec->fir_taps16[1][i] += (int16_t) ((exp+(1<<14)) >> 15);
-    }
+	int i;
+
+	int offset1;
+	int offset2;
+	int factor;
+	int exp;
+
+	if (shift > 0)
+		factor = clean << shift;
+	else
+		factor = clean >> -shift;
+
+	/* Update the FIR taps */
+
+	offset2 = ec->curr_pos;
+	offset1 = ec->taps - offset2;
+
+	for (i = ec->taps - 1; i >= offset1; i--) {
+		exp = (ec->fir_state_bg.history[i - offset1] * factor);
+		ec->fir_taps16[1][i] += (int16_t) ((exp + (1 << 14)) >> 15);
+	}
+	for (; i >= 0; i--) {
+		exp = (ec->fir_state_bg.history[i + offset2] * factor);
+		ec->fir_taps16[1][i] += (int16_t) ((exp + (1 << 14)) >> 15);
+	}
 }
 #endif
 
-
 struct oslec_state *oslec_create(int len, int adaption_mode)
 {
-    struct oslec_state *ec;
-    int i;
-
-    ec = kzalloc(sizeof(*ec), GFP_KERNEL);
-    if (!ec)
-        return NULL;
-
-    ec->taps = len;
-    ec->log2taps = top_bit(len);
-    ec->curr_pos = ec->taps - 1;
-
-    for (i = 0; i < 2; i++) {
-        ec->fir_taps16[i] = kcalloc(ec->taps, sizeof(int16_t), GFP_KERNEL);
-        if (!ec->fir_taps16[i])
-	    goto error_oom;
-    }
-
-    fir16_create(&ec->fir_state,
-                 ec->fir_taps16[0],
-                 ec->taps);
-    fir16_create(&ec->fir_state_bg,
-                 ec->fir_taps16[1],
-                 ec->taps);
-
-    for(i=0; i<5; i++) {
-      ec->xvtx[i] = ec->yvtx[i] = ec->xvrx[i] = ec->yvrx[i] = 0;
-    }
-
-    ec->cng_level = 1000;
-    oslec_adaption_mode(ec, adaption_mode);
-
-    ec->snapshot = kcalloc(ec->taps, sizeof(int16_t), GFP_KERNEL);
-    if (!ec->snapshot)
-        goto error_oom;
-
-    ec->cond_met = 0;
-    ec->Pstates = 0;
-    ec->Ltxacc = ec->Lrxacc = ec->Lcleanacc = ec->Lclean_bgacc = 0;
-    ec->Ltx = ec->Lrx = ec->Lclean = ec->Lclean_bg = 0;
-    ec->tx_1 = ec->tx_2 = ec->rx_1 = ec->rx_2 = 0;
-    ec->Lbgn = ec->Lbgn_acc = 0;
-    ec->Lbgn_upper = 200;
-    ec->Lbgn_upper_acc = ec->Lbgn_upper << 13;
-
-    return  ec;
-
-error_oom:
-    for (i = 0; i < 2; i++)
-        kfree(ec->fir_taps16[i]);
-
-    kfree(ec);
-    return NULL;
+	struct oslec_state *ec;
+	int i;
+
+	ec = kzalloc(sizeof(*ec), GFP_KERNEL);
+	if (!ec)
+		return NULL;
+
+	ec->taps = len;
+	ec->log2taps = top_bit(len);
+	ec->curr_pos = ec->taps - 1;
+
+	for (i = 0; i < 2; i++) {
+		ec->fir_taps16[i] =
+		    kcalloc(ec->taps, sizeof(int16_t), GFP_KERNEL);
+		if (!ec->fir_taps16[i])
+			goto error_oom;
+	}
+
+	fir16_create(&ec->fir_state, ec->fir_taps16[0], ec->taps);
+	fir16_create(&ec->fir_state_bg, ec->fir_taps16[1], ec->taps);
+
+	for (i = 0; i < 5; i++) {
+		ec->xvtx[i] = ec->yvtx[i] = ec->xvrx[i] = ec->yvrx[i] = 0;
+	}
+
+	ec->cng_level = 1000;
+	oslec_adaption_mode(ec, adaption_mode);
+
+	ec->snapshot = kcalloc(ec->taps, sizeof(int16_t), GFP_KERNEL);
+	if (!ec->snapshot)
+		goto error_oom;
+
+	ec->cond_met = 0;
+	ec->Pstates = 0;
+	ec->Ltxacc = ec->Lrxacc = ec->Lcleanacc = ec->Lclean_bgacc = 0;
+	ec->Ltx = ec->Lrx = ec->Lclean = ec->Lclean_bg = 0;
+	ec->tx_1 = ec->tx_2 = ec->rx_1 = ec->rx_2 = 0;
+	ec->Lbgn = ec->Lbgn_acc = 0;
+	ec->Lbgn_upper = 200;
+	ec->Lbgn_upper_acc = ec->Lbgn_upper << 13;
+
+	return ec;
+
+      error_oom:
+	for (i = 0; i < 2; i++)
+		kfree(ec->fir_taps16[i]);
+
+	kfree(ec);
+	return NULL;
 }
+
 EXPORT_SYMBOL_GPL(oslec_create);
 
 void oslec_free(struct oslec_state *ec)
@@ -294,293 +288,300 @@ void oslec_free(struct oslec_state *ec)
 
 	fir16_free(&ec->fir_state);
 	fir16_free(&ec->fir_state_bg);
-	for (i = 0;  i < 2;  i++)
+	for (i = 0; i < 2; i++)
 		kfree(ec->fir_taps16[i]);
 	kfree(ec->snapshot);
 	kfree(ec);
 }
+
 EXPORT_SYMBOL_GPL(oslec_free);
 
 void oslec_adaption_mode(struct oslec_state *ec, int adaption_mode)
 {
-    ec->adaption_mode = adaption_mode;
+	ec->adaption_mode = adaption_mode;
 }
+
 EXPORT_SYMBOL_GPL(oslec_adaption_mode);
 
 void oslec_flush(struct oslec_state *ec)
 {
-    int i;
+	int i;
 
-    ec->Ltxacc = ec->Lrxacc = ec->Lcleanacc = ec->Lclean_bgacc = 0;
-    ec->Ltx = ec->Lrx = ec->Lclean = ec->Lclean_bg = 0;
-    ec->tx_1 = ec->tx_2 = ec->rx_1 = ec->rx_2 = 0;
+	ec->Ltxacc = ec->Lrxacc = ec->Lcleanacc = ec->Lclean_bgacc = 0;
+	ec->Ltx = ec->Lrx = ec->Lclean = ec->Lclean_bg = 0;
+	ec->tx_1 = ec->tx_2 = ec->rx_1 = ec->rx_2 = 0;
 
-    ec->Lbgn = ec->Lbgn_acc = 0;
-    ec->Lbgn_upper = 200;
-    ec->Lbgn_upper_acc = ec->Lbgn_upper << 13;
+	ec->Lbgn = ec->Lbgn_acc = 0;
+	ec->Lbgn_upper = 200;
+	ec->Lbgn_upper_acc = ec->Lbgn_upper << 13;
 
-    ec->nonupdate_dwell = 0;
+	ec->nonupdate_dwell = 0;
 
-    fir16_flush(&ec->fir_state);
-    fir16_flush(&ec->fir_state_bg);
-    ec->fir_state.curr_pos = ec->taps - 1;
-    ec->fir_state_bg.curr_pos = ec->taps - 1;
-    for (i = 0;  i < 2;  i++)
-        memset(ec->fir_taps16[i], 0, ec->taps*sizeof(int16_t));
+	fir16_flush(&ec->fir_state);
+	fir16_flush(&ec->fir_state_bg);
+	ec->fir_state.curr_pos = ec->taps - 1;
+	ec->fir_state_bg.curr_pos = ec->taps - 1;
+	for (i = 0; i < 2; i++)
+		memset(ec->fir_taps16[i], 0, ec->taps * sizeof(int16_t));
 
-    ec->curr_pos = ec->taps - 1;
-    ec->Pstates = 0;
+	ec->curr_pos = ec->taps - 1;
+	ec->Pstates = 0;
 }
+
 EXPORT_SYMBOL_GPL(oslec_flush);
 
-void oslec_snapshot(struct oslec_state *ec) {
-    memcpy(ec->snapshot, ec->fir_taps16[0], ec->taps*sizeof(int16_t));
+void oslec_snapshot(struct oslec_state *ec)
+{
+	memcpy(ec->snapshot, ec->fir_taps16[0], ec->taps * sizeof(int16_t));
 }
+
 EXPORT_SYMBOL_GPL(oslec_snapshot);
 
 /* Dual Path Echo Canceller ------------------------------------------------*/
 
 int16_t oslec_update(struct oslec_state *ec, int16_t tx, int16_t rx)
 {
-    int32_t echo_value;
-    int clean_bg;
-    int tmp, tmp1;
-
-    /* Input scaling was found be required to prevent problems when tx
-       starts clipping.  Another possible way to handle this would be the
-       filter coefficent scaling. */
-
-    ec->tx = tx; ec->rx = rx;
-    tx >>=1;
-    rx >>=1;
-
-    /*
-       Filter DC, 3dB point is 160Hz (I think), note 32 bit precision required
-       otherwise values do not track down to 0. Zero at DC, Pole at (1-Beta)
-       only real axis.  Some chip sets (like Si labs) don't need
-       this, but something like a $10 X100P card does.  Any DC really slows
-       down convergence.
-
-       Note: removes some low frequency from the signal, this reduces
-       the speech quality when listening to samples through headphones
-       but may not be obvious through a telephone handset.
-
-       Note that the 3dB frequency in radians is approx Beta, e.g. for
-       Beta = 2^(-3) = 0.125, 3dB freq is 0.125 rads = 159Hz.
-    */
-
-    if (ec->adaption_mode & ECHO_CAN_USE_RX_HPF) {
-      tmp = rx << 15;
+	int32_t echo_value;
+	int clean_bg;
+	int tmp, tmp1;
+
+	/* Input scaling was found be required to prevent problems when tx
+	   starts clipping.  Another possible way to handle this would be the
+	   filter coefficent scaling. */
+
+	ec->tx = tx;
+	ec->rx = rx;
+	tx >>= 1;
+	rx >>= 1;
+
+	/*
+	   Filter DC, 3dB point is 160Hz (I think), note 32 bit precision required
+	   otherwise values do not track down to 0. Zero at DC, Pole at (1-Beta)
+	   only real axis.  Some chip sets (like Si labs) don't need
+	   this, but something like a $10 X100P card does.  Any DC really slows
+	   down convergence.
+
+	   Note: removes some low frequency from the signal, this reduces
+	   the speech quality when listening to samples through headphones
+	   but may not be obvious through a telephone handset.
+
+	   Note that the 3dB frequency in radians is approx Beta, e.g. for
+	   Beta = 2^(-3) = 0.125, 3dB freq is 0.125 rads = 159Hz.
+	 */
+
+	if (ec->adaption_mode & ECHO_CAN_USE_RX_HPF) {
+		tmp = rx << 15;
 #if 1
-        /* Make sure the gain of the HPF is 1.0. This can still saturate a little under
-           impulse conditions, and it might roll to 32768 and need clipping on sustained peak
-           level signals. However, the scale of such clipping is small, and the error due to
-           any saturation should not markedly affect the downstream processing. */
-        tmp -= (tmp >> 4);
+		/* Make sure the gain of the HPF is 1.0. This can still saturate a little under
+		   impulse conditions, and it might roll to 32768 and need clipping on sustained peak
+		   level signals. However, the scale of such clipping is small, and the error due to
+		   any saturation should not markedly affect the downstream processing. */
+		tmp -= (tmp >> 4);
 #endif
-      ec->rx_1 += -(ec->rx_1>>DC_LOG2BETA) + tmp - ec->rx_2;
+		ec->rx_1 += -(ec->rx_1 >> DC_LOG2BETA) + tmp - ec->rx_2;
+
+		/* hard limit filter to prevent clipping.  Note that at this stage
+		   rx should be limited to +/- 16383 due to right shift above */
+		tmp1 = ec->rx_1 >> 15;
+		if (tmp1 > 16383)
+			tmp1 = 16383;
+		if (tmp1 < -16383)
+			tmp1 = -16383;
+		rx = tmp1;
+		ec->rx_2 = tmp;
+	}
 
-      /* hard limit filter to prevent clipping.  Note that at this stage
-	 rx should be limited to +/- 16383 due to right shift above */
-      tmp1 = ec->rx_1 >> 15;
-      if (tmp1 > 16383) tmp1 = 16383;
-      if (tmp1 < -16383) tmp1 = -16383;
-      rx = tmp1;
-      ec->rx_2 = tmp;
-    }
+	/* Block average of power in the filter states.  Used for
+	   adaption power calculation. */
 
-    /* Block average of power in the filter states.  Used for
-       adaption power calculation. */
+	{
+		int new, old;
+
+		/* efficient "out with the old and in with the new" algorithm so
+		   we don't have to recalculate over the whole block of
+		   samples. */
+		new = (int)tx *(int)tx;
+		old = (int)ec->fir_state.history[ec->fir_state.curr_pos] *
+		    (int)ec->fir_state.history[ec->fir_state.curr_pos];
+		ec->Pstates +=
+		    ((new - old) + (1 << ec->log2taps)) >> ec->log2taps;
+		if (ec->Pstates < 0)
+			ec->Pstates = 0;
+	}
 
-    {
-	int new, old;
+	/* Calculate short term average levels using simple single pole IIRs */
 
-	/* efficient "out with the old and in with the new" algorithm so
-	   we don't have to recalculate over the whole block of
-	   samples. */
-	new = (int)tx * (int)tx;
-	old = (int)ec->fir_state.history[ec->fir_state.curr_pos] *
-              (int)ec->fir_state.history[ec->fir_state.curr_pos];
-	ec->Pstates += ((new - old) + (1<<ec->log2taps)) >> ec->log2taps;
-	if (ec->Pstates < 0) ec->Pstates = 0;
-    }
-
-    /* Calculate short term average levels using simple single pole IIRs */
-
-    ec->Ltxacc += abs(tx) - ec->Ltx;
-    ec->Ltx = (ec->Ltxacc + (1<<4)) >> 5;
-    ec->Lrxacc += abs(rx) - ec->Lrx;
-    ec->Lrx = (ec->Lrxacc + (1<<4)) >> 5;
-
-    /* Foreground filter ---------------------------------------------------*/
-
-    ec->fir_state.coeffs = ec->fir_taps16[0];
-    echo_value = fir16(&ec->fir_state, tx);
-    ec->clean = rx - echo_value;
-    ec->Lcleanacc += abs(ec->clean) - ec->Lclean;
-    ec->Lclean = (ec->Lcleanacc + (1<<4)) >> 5;
-
-    /* Background filter ---------------------------------------------------*/
-
-    echo_value = fir16(&ec->fir_state_bg, tx);
-    clean_bg = rx - echo_value;
-    ec->Lclean_bgacc += abs(clean_bg) - ec->Lclean_bg;
-    ec->Lclean_bg = (ec->Lclean_bgacc + (1<<4)) >> 5;
-
-    /* Background Filter adaption -----------------------------------------*/
-
-    /* Almost always adap bg filter, just simple DT and energy
-       detection to minimise adaption in cases of strong double talk.
-       However this is not critical for the dual path algorithm.
-    */
-    ec->factor = 0;
-    ec->shift = 0;
-    if ((ec->nonupdate_dwell == 0)) {
-	int   P, logP, shift;
-
-	/* Determine:
-
-	   f = Beta * clean_bg_rx/P ------ (1)
-
-	   where P is the total power in the filter states.
-
-	   The Boffins have shown that if we obey (1) we converge
-	   quickly and avoid instability.
-
-	   The correct factor f must be in Q30, as this is the fixed
-	   point format required by the lms_adapt_bg() function,
-	   therefore the scaled version of (1) is:
-
-	   (2^30) * f  = (2^30) * Beta * clean_bg_rx/P
-	       factor  = (2^30) * Beta * clean_bg_rx/P         ----- (2)
-
-	   We have chosen Beta = 0.25 by experiment, so:
-
-	       factor  = (2^30) * (2^-2) * clean_bg_rx/P
-
-                                       (30 - 2 - log2(P))
-	       factor  = clean_bg_rx 2                         ----- (3)
-
-	   To avoid a divide we approximate log2(P) as top_bit(P),
-	   which returns the position of the highest non-zero bit in
-	   P.  This approximation introduces an error as large as a
-	   factor of 2, but the algorithm seems to handle it OK.
-
-	   Come to think of it a divide may not be a big deal on a
-	   modern DSP, so its probably worth checking out the cycles
-	   for a divide versus a top_bit() implementation.
-	*/
-
-	P = MIN_TX_POWER_FOR_ADAPTION + ec->Pstates;
-	logP = top_bit(P) + ec->log2taps;
-	shift = 30 - 2 - logP;
-	ec->shift = shift;
-
-	lms_adapt_bg(ec, clean_bg, shift);
-    }
-
-    /* very simple DTD to make sure we dont try and adapt with strong
-       near end speech */
-
-    ec->adapt = 0;
-    if ((ec->Lrx > MIN_RX_POWER_FOR_ADAPTION) && (ec->Lrx > ec->Ltx))
-	ec->nonupdate_dwell = DTD_HANGOVER;
-    if (ec->nonupdate_dwell)
-	ec->nonupdate_dwell--;
+	ec->Ltxacc += abs(tx) - ec->Ltx;
+	ec->Ltx = (ec->Ltxacc + (1 << 4)) >> 5;
+	ec->Lrxacc += abs(rx) - ec->Lrx;
+	ec->Lrx = (ec->Lrxacc + (1 << 4)) >> 5;
 
-    /* Transfer logic ------------------------------------------------------*/
+	/* Foreground filter --------------------------------------------------- */
 
-    /* These conditions are from the dual path paper [1], I messed with
-       them a bit to improve performance. */
+	ec->fir_state.coeffs = ec->fir_taps16[0];
+	echo_value = fir16(&ec->fir_state, tx);
+	ec->clean = rx - echo_value;
+	ec->Lcleanacc += abs(ec->clean) - ec->Lclean;
+	ec->Lclean = (ec->Lcleanacc + (1 << 4)) >> 5;
 
-    if ((ec->adaption_mode & ECHO_CAN_USE_ADAPTION) &&
-	(ec->nonupdate_dwell == 0) &&
-	(8*ec->Lclean_bg < 7*ec->Lclean) /* (ec->Lclean_bg < 0.875*ec->Lclean) */ &&
-	(8*ec->Lclean_bg < ec->Ltx)      /* (ec->Lclean_bg < 0.125*ec->Ltx)    */ )
-    {
-	if (ec->cond_met == 6) {
-	    /* BG filter has had better results for 6 consecutive samples */
-	    ec->adapt = 1;
-	    memcpy(ec->fir_taps16[0], ec->fir_taps16[1], ec->taps*sizeof(int16_t));
-	}
-	else
-	    ec->cond_met++;
-    }
-    else
-	ec->cond_met = 0;
+	/* Background filter --------------------------------------------------- */
 
-    /* Non-Linear Processing ---------------------------------------------------*/
+	echo_value = fir16(&ec->fir_state_bg, tx);
+	clean_bg = rx - echo_value;
+	ec->Lclean_bgacc += abs(clean_bg) - ec->Lclean_bg;
+	ec->Lclean_bg = (ec->Lclean_bgacc + (1 << 4)) >> 5;
 
-    ec->clean_nlp = ec->clean;
-    if (ec->adaption_mode & ECHO_CAN_USE_NLP)
-    {
-        /* Non-linear processor - a fancy way to say "zap small signals, to avoid
-           residual echo due to (uLaw/ALaw) non-linearity in the channel.". */
+	/* Background Filter adaption ----------------------------------------- */
 
-      if ((16*ec->Lclean < ec->Ltx))
-      {
-	/* Our e/c has improved echo by at least 24 dB (each factor of 2 is 6dB,
-	   so 2*2*2*2=16 is the same as 6+6+6+6=24dB) */
-        if (ec->adaption_mode & ECHO_CAN_USE_CNG)
-	{
-	    ec->cng_level = ec->Lbgn;
-
-	    /* Very elementary comfort noise generation.  Just random
-	       numbers rolled off very vaguely Hoth-like.  DR: This
-	       noise doesn't sound quite right to me - I suspect there
-	       are some overlfow issues in the filtering as it's too
-	       "crackly".  TODO: debug this, maybe just play noise at
-	       high level or look at spectrum.
-	    */
-
-	    ec->cng_rndnum = 1664525U*ec->cng_rndnum + 1013904223U;
-	    ec->cng_filter = ((ec->cng_rndnum & 0xFFFF) - 32768 + 5*ec->cng_filter) >> 3;
-	    ec->clean_nlp = (ec->cng_filter*ec->cng_level*8) >> 14;
-
-        }
-        else if (ec->adaption_mode & ECHO_CAN_USE_CLIP)
-	{
-	    /* This sounds much better than CNG */
-	    if (ec->clean_nlp > ec->Lbgn)
-	      ec->clean_nlp = ec->Lbgn;
-	    if (ec->clean_nlp < -ec->Lbgn)
-	      ec->clean_nlp = -ec->Lbgn;
+	/* Almost always adap bg filter, just simple DT and energy
+	   detection to minimise adaption in cases of strong double talk.
+	   However this is not critical for the dual path algorithm.
+	 */
+	ec->factor = 0;
+	ec->shift = 0;
+	if ((ec->nonupdate_dwell == 0)) {
+		int P, logP, shift;
+
+		/* Determine:
+
+		   f = Beta * clean_bg_rx/P ------ (1)
+
+		   where P is the total power in the filter states.
+
+		   The Boffins have shown that if we obey (1) we converge
+		   quickly and avoid instability.
+
+		   The correct factor f must be in Q30, as this is the fixed
+		   point format required by the lms_adapt_bg() function,
+		   therefore the scaled version of (1) is:
+
+		   (2^30) * f  = (2^30) * Beta * clean_bg_rx/P
+		   factor  = (2^30) * Beta * clean_bg_rx/P         ----- (2)
+
+		   We have chosen Beta = 0.25 by experiment, so:
+
+		   factor  = (2^30) * (2^-2) * clean_bg_rx/P
+
+		   (30 - 2 - log2(P))
+		   factor  = clean_bg_rx 2                         ----- (3)
+
+		   To avoid a divide we approximate log2(P) as top_bit(P),
+		   which returns the position of the highest non-zero bit in
+		   P.  This approximation introduces an error as large as a
+		   factor of 2, but the algorithm seems to handle it OK.
+
+		   Come to think of it a divide may not be a big deal on a
+		   modern DSP, so its probably worth checking out the cycles
+		   for a divide versus a top_bit() implementation.
+		 */
+
+		P = MIN_TX_POWER_FOR_ADAPTION + ec->Pstates;
+		logP = top_bit(P) + ec->log2taps;
+		shift = 30 - 2 - logP;
+		ec->shift = shift;
+
+		lms_adapt_bg(ec, clean_bg, shift);
 	}
-	else
-        {
-	  /* just mute the residual, doesn't sound very good, used mainly
-	     in G168 tests */
-          ec->clean_nlp = 0;
-        }
-      }
-      else {
-	  /* Background noise estimator.  I tried a few algorithms
-	     here without much luck.  This very simple one seems to
-	     work best, we just average the level using a slow (1 sec
-	     time const) filter if the current level is less than a
-	     (experimentally derived) constant.  This means we dont
-	     include high level signals like near end speech.  When
-	     combined with CNG or especially CLIP seems to work OK.
-	  */
-	  if (ec->Lclean < 40) {
-	      ec->Lbgn_acc += abs(ec->clean) - ec->Lbgn;
-	      ec->Lbgn = (ec->Lbgn_acc + (1<<11)) >> 12;
-	  }
-       }
-    }
-
-    /* Roll around the taps buffer */
-    if (ec->curr_pos <= 0)
-        ec->curr_pos = ec->taps;
-    ec->curr_pos--;
-
-    if (ec->adaption_mode & ECHO_CAN_DISABLE)
-      ec->clean_nlp = rx;
-
-    /* Output scaled back up again to match input scaling */
-
-    return (int16_t) ec->clean_nlp << 1;
+
+	/* very simple DTD to make sure we dont try and adapt with strong
+	   near end speech */
+
+	ec->adapt = 0;
+	if ((ec->Lrx > MIN_RX_POWER_FOR_ADAPTION) && (ec->Lrx > ec->Ltx))
+		ec->nonupdate_dwell = DTD_HANGOVER;
+	if (ec->nonupdate_dwell)
+		ec->nonupdate_dwell--;
+
+	/* Transfer logic ------------------------------------------------------ */
+
+	/* These conditions are from the dual path paper [1], I messed with
+	   them a bit to improve performance. */
+
+	if ((ec->adaption_mode & ECHO_CAN_USE_ADAPTION) &&
+	    (ec->nonupdate_dwell == 0) &&
+	    (8 * ec->Lclean_bg <
+	     7 * ec->Lclean) /* (ec->Lclean_bg < 0.875*ec->Lclean) */ &&
+	    (8 * ec->Lclean_bg <
+	     ec->Ltx) /* (ec->Lclean_bg < 0.125*ec->Ltx)    */ ) {
+		if (ec->cond_met == 6) {
+			/* BG filter has had better results for 6 consecutive samples */
+			ec->adapt = 1;
+			memcpy(ec->fir_taps16[0], ec->fir_taps16[1],
+			       ec->taps * sizeof(int16_t));
+		} else
+			ec->cond_met++;
+	} else
+		ec->cond_met = 0;
+
+	/* Non-Linear Processing --------------------------------------------------- */
+
+	ec->clean_nlp = ec->clean;
+	if (ec->adaption_mode & ECHO_CAN_USE_NLP) {
+		/* Non-linear processor - a fancy way to say "zap small signals, to avoid
+		   residual echo due to (uLaw/ALaw) non-linearity in the channel.". */
+
+		if ((16 * ec->Lclean < ec->Ltx)) {
+			/* Our e/c has improved echo by at least 24 dB (each factor of 2 is 6dB,
+			   so 2*2*2*2=16 is the same as 6+6+6+6=24dB) */