提交 fdaaee6c 编写于 作者: K Klaus Schmidinger 提交者: Mauro Carvalho Chehab

[media] DVB: stb0899: speed up getting BER values

stb0899_read_ber() takes 500ms (half a second!) to deliver the current
BER value. Apparently it takes 5 subsequent readings, with a 100ms pause
between them (and even before the first one). This is a real performance
brake if an application freqeuently reads the BER of several devices.
The attached patch reduces this to a single reading, with no more pausing.
I didn't observe any negative side effects of this change.
Signed-off-by: NKlaus Schmidinger <Klaus.Schmidinger@tvdr.de>
Cc: Manu Abraham <abraham.manu@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>
上级 4a628170
...@@ -1129,7 +1129,6 @@ static int stb0899_read_ber(struct dvb_frontend *fe, u32 *ber) ...@@ -1129,7 +1129,6 @@ static int stb0899_read_ber(struct dvb_frontend *fe, u32 *ber)
struct stb0899_internal *internal = &state->internal; struct stb0899_internal *internal = &state->internal;
u8 lsb, msb; u8 lsb, msb;
u32 i;
*ber = 0; *ber = 0;
...@@ -1137,14 +1136,9 @@ static int stb0899_read_ber(struct dvb_frontend *fe, u32 *ber) ...@@ -1137,14 +1136,9 @@ static int stb0899_read_ber(struct dvb_frontend *fe, u32 *ber)
case SYS_DVBS: case SYS_DVBS:
case SYS_DSS: case SYS_DSS:
if (internal->lock) { if (internal->lock) {
/* average 5 BER values */ lsb = stb0899_read_reg(state, STB0899_ECNT1L);
for (i = 0; i < 5; i++) { msb = stb0899_read_reg(state, STB0899_ECNT1M);
msleep(100); *ber = MAKEWORD16(msb, lsb);
lsb = stb0899_read_reg(state, STB0899_ECNT1L);
msb = stb0899_read_reg(state, STB0899_ECNT1M);
*ber += MAKEWORD16(msb, lsb);
}
*ber /= 5;
/* Viterbi Check */ /* Viterbi Check */
if (STB0899_GETFIELD(VSTATUS_PRFVIT, internal->v_status)) { if (STB0899_GETFIELD(VSTATUS_PRFVIT, internal->v_status)) {
/* Error Rate */ /* Error Rate */
...@@ -1157,13 +1151,9 @@ static int stb0899_read_ber(struct dvb_frontend *fe, u32 *ber) ...@@ -1157,13 +1151,9 @@ static int stb0899_read_ber(struct dvb_frontend *fe, u32 *ber)
break; break;
case SYS_DVBS2: case SYS_DVBS2:
if (internal->lock) { if (internal->lock) {
/* Average 5 PER values */ lsb = stb0899_read_reg(state, STB0899_ECNT1L);
for (i = 0; i < 5; i++) { msb = stb0899_read_reg(state, STB0899_ECNT1M);
msleep(100); *ber = MAKEWORD16(msb, lsb);
lsb = stb0899_read_reg(state, STB0899_ECNT1L);
msb = stb0899_read_reg(state, STB0899_ECNT1M);
*ber += MAKEWORD16(msb, lsb);
}
/* ber = ber * 10 ^ 7 */ /* ber = ber * 10 ^ 7 */
*ber *= 10000000; *ber *= 10000000;
*ber /= (-1 + (1 << (4 + 2 * STB0899_GETFIELD(NOE, internal->err_ctrl)))); *ber /= (-1 + (1 << (4 + 2 * STB0899_GETFIELD(NOE, internal->err_ctrl))));
......
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