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[2/5] m88ds3103: calculate DiSEqC message sending time

Message ID 1467243588-26204-2-git-send-email-crope@iki.fi (mailing list archive)
State New, archived
Headers show

Commit Message

Antti Palosaari June 29, 2016, 11:39 p.m. UTC
DiSEqC message sending takes 13.5 ms per byte, which is 54 ms total
when typical 4 byte message is sent. Don't hard-code time limit to
54 ms, but calculate it. Time limit is only used to determine when to
start poll "DiSEqC Tx ready" status from the chip.

Signed-off-by: Antti Palosaari <crope@iki.fi>
---
 drivers/media/dvb-frontends/m88ds3103.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/media/dvb-frontends/m88ds3103.c b/drivers/media/dvb-frontends/m88ds3103.c
index 7c19601..6f03ca8 100644
--- a/drivers/media/dvb-frontends/m88ds3103.c
+++ b/drivers/media/dvb-frontends/m88ds3103.c
@@ -1116,8 +1116,9 @@  static int m88ds3103_diseqc_send_master_cmd(struct dvb_frontend *fe,
 	#define SEND_MASTER_CMD_TIMEOUT 120
 	timeout = jiffies + msecs_to_jiffies(SEND_MASTER_CMD_TIMEOUT);
 
-	/* DiSEqC message typical period is 54 ms */
-	usleep_range(50000, 54000);
+	/* DiSEqC message period is 13.5 ms per byte */
+	utmp = diseqc_cmd->msg_len * 13500;
+	usleep_range(utmp - 4000, utmp);
 
 	for (utmp = 1; !time_after(jiffies, timeout) && utmp;) {
 		ret = regmap_read(dev->regmap, 0xa1, &utmp);