[media] tuner-xc2028: Fix signal strength report

There are several bugs at the signal strength algorithm:

	- It is using logical OR, instead of bit OR;
	- It doesn't wait up to 18 ms as it should;
	- the strength range is not ok.

Rework on it, in order to make it work.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/common/tuners/tuner-xc2028.c b/drivers/media/common/tuners/tuner-xc2028.c
index 9638a69..42fdf5c 100644 (file)
--- a/drivers/media/common/tuners/tuner-xc2028.c
+++ b/drivers/media/common/tuners/tuner-xc2028.c
@@ -903,7 +903,7 @@ static int xc2028_signal(struct dvb_frontend *fe, u16 *strength)
 {
        struct xc2028_data *priv = fe->tuner_priv;
        u16                 frq_lock, signal = 0;
-       int                 rc;
+       int                 rc, i;
 
        tuner_dbg("%s called\n", __func__);
 
@@ -914,21 +914,28 @@ static int xc2028_signal(struct dvb_frontend *fe, u16 *strength)
        mutex_lock(&priv->lock);
 
        /* Sync Lock Indicator */
-       rc = xc2028_get_reg(priv, XREG_LOCK, &frq_lock);
-       if (rc < 0)
-               goto ret;
+       for (i = 0; i < 3; i++) {
+               rc = xc2028_get_reg(priv, XREG_LOCK, &frq_lock);
+               if (rc < 0)
+                       goto ret;
 
-       /* Frequency is locked */
-       if (frq_lock == 1)
-               signal = 1 << 11;
+               if (frq_lock)
+                       break;
+               msleep(6);
+       }
+
+       /* Frequency was not locked */
+       if (frq_lock == 2)
+               goto ret;
 
        /* Get SNR of the video signal */
        rc = xc2028_get_reg(priv, XREG_SNR, &signal);
        if (rc < 0)
                goto ret;
 
-       /* Use both frq_lock and signal to generate the result */
-       signal = signal || ((signal & 0x07) << 12);
+       /* Signal level is 3 bits only */
+
+       signal = ((1 << 12) - 1) | ((signal & 0x07) << 12);
 
 ret:
        mutex_unlock(&priv->lock);