[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>

1 files changed, 16 insertions, 9 deletions

diff --git a/drivers/media/common/tuners/tuner-xc2028.c b/drivers/media/common/tuners/tuner-xc2028.c
index 9638a69f36b2..42fdf5c57091 100644
--- 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);