[media] mb86a20s: fix the locking logic
authorMauro Carvalho Chehab <mchehab@osg.samsung.com>
Sun, 4 Sep 2016 13:16:18 +0000 (10:16 -0300)
committerMauro Carvalho Chehab <mchehab@s-opensource.com>
Mon, 5 Sep 2016 18:26:29 +0000 (15:26 -0300)
On this frontend, it takes a while to start output normal
TS data. That only happens on state S9. On S8, the TS output
is enabled, but it is not reliable enough.

However, the zigzag loop is too fast to let it sync.

As, on practical tests, the zigzag software loop doesn't
seem to be helping, but just slowing down the tuning, let's
switch to hardware algorithm, as the tuners used on such
devices are capable of work with frequency drifts without
any help from software.

Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
drivers/media/dvb-frontends/mb86a20s.c

index 41325328a22ed2f9581eb0b79fcbf1c10932a6c1..a9fb7d45d9caee438c6f9bd6d7607cd4d29cd927 100644 (file)
@@ -318,7 +318,11 @@ static int mb86a20s_read_status(struct dvb_frontend *fe, enum fe_status *status)
        if (val >= 7)
                *status |= FE_HAS_SYNC;
 
-       if (val >= 8)                           /* Maybe 9? */
+       /*
+        * Actually, on state S8, it starts receiving TS, but the TS
+        * output is only on normal state after the transition to S9.
+        */
+       if (val >= 9)
                *status |= FE_HAS_LOCK;
 
        dev_dbg(&state->i2c->dev, "%s: Status = 0x%02x (state = %d)\n",
@@ -2058,6 +2062,11 @@ static void mb86a20s_release(struct dvb_frontend *fe)
        kfree(state);
 }
 
+static int mb86a20s_get_frontend_algo(struct dvb_frontend *fe)
+{
+        return DVBFE_ALGO_HW;
+}
+
 static struct dvb_frontend_ops mb86a20s_ops;
 
 struct dvb_frontend *mb86a20s_attach(const struct mb86a20s_config *config,
@@ -2130,6 +2139,7 @@ static struct dvb_frontend_ops mb86a20s_ops = {
        .read_status = mb86a20s_read_status_and_stats,
        .read_signal_strength = mb86a20s_read_signal_strength_from_cache,
        .tune = mb86a20s_tune,
+       .get_frontend_algo = mb86a20s_get_frontend_algo,
 };
 
 MODULE_DESCRIPTION("DVB Frontend module for Fujitsu mb86A20s hardware");