From fdaaee6c4a63e364b7f9c8bfdb218e6aaa65f1cf Mon Sep 17 00:00:00 2001 From: Klaus Schmidinger Date: Sat, 2 Jun 2012 11:04:17 -0300 Subject: [PATCH] [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: Klaus Schmidinger Cc: Manu Abraham Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb/frontends/stb0899_drv.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-) diff --git a/drivers/media/dvb/frontends/stb0899_drv.c b/drivers/media/dvb/frontends/stb0899_drv.c index 8b0dc74a3298..5d7f8a9b451b 100644 --- a/drivers/media/dvb/frontends/stb0899_drv.c +++ b/drivers/media/dvb/frontends/stb0899_drv.c @@ -1129,7 +1129,6 @@ static int stb0899_read_ber(struct dvb_frontend *fe, u32 *ber) struct stb0899_internal *internal = &state->internal; u8 lsb, msb; - u32 i; *ber = 0; @@ -1137,14 +1136,9 @@ static int stb0899_read_ber(struct dvb_frontend *fe, u32 *ber) case SYS_DVBS: case SYS_DSS: if (internal->lock) { - /* average 5 BER values */ - for (i = 0; i < 5; i++) { - msleep(100); - lsb = stb0899_read_reg(state, STB0899_ECNT1L); - msb = stb0899_read_reg(state, STB0899_ECNT1M); - *ber += MAKEWORD16(msb, lsb); - } - *ber /= 5; + lsb = stb0899_read_reg(state, STB0899_ECNT1L); + msb = stb0899_read_reg(state, STB0899_ECNT1M); + *ber = MAKEWORD16(msb, lsb); /* Viterbi Check */ if (STB0899_GETFIELD(VSTATUS_PRFVIT, internal->v_status)) { /* Error Rate */ @@ -1157,13 +1151,9 @@ static int stb0899_read_ber(struct dvb_frontend *fe, u32 *ber) break; case SYS_DVBS2: if (internal->lock) { - /* Average 5 PER values */ - for (i = 0; i < 5; i++) { - msleep(100); - lsb = stb0899_read_reg(state, STB0899_ECNT1L); - msb = stb0899_read_reg(state, STB0899_ECNT1M); - *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 *= 10000000; *ber /= (-1 + (1 << (4 + 2 * STB0899_GETFIELD(NOE, internal->err_ctrl)))); -- 2.20.1