[PATCH] dvb: core: add workaround for tuning problem

Add workaround for signal lock loss issue, where the frontend loses the signal
after some hours without any visible reason.

Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 25 insertions, 3 deletions

diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
index e561ac1e1b16..a8bc84240b50 100644
--- a/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -42,6 +42,8 @@
 #include "dvb_frontend.h"
 #include "dvbdev.h"
 
+// #define DEBUG_LOCKLOSS 1
+
 static int dvb_frontend_debug;
 static int dvb_shutdown_timeout = 5;
 static int dvb_force_auto_inversion;
@@ -113,6 +115,7 @@ struct dvb_frontend_private {
         int exit;
         int wakeup;
         fe_status_t status;
+        fe_sec_tone_mode_t tone;
 };
 
 
@@ -434,9 +437,26 @@ static int dvb_frontend_thread(void *data)
                         /* we're tuned, and the lock is still good... */
                         if (s & FE_HAS_LOCK)
                                 continue;
-                        else {
-                                /* if we _WERE_ tuned, but now don't have a lock,
-                                 * need to zigzag */
+                        else { /* if we _WERE_ tuned, but now don't have a lock */
+#ifdef DEBUG_LOCKLOSS
+                                /* first of all try setting the tone again if it was on - this
+                                 * sometimes works around problems with noisy power supplies */
+                                if (fe->ops->set_tone && (fepriv->tone == SEC_TONE_ON)) {
+                                        fe->ops->set_tone(fe, fepriv->tone);
+                                        mdelay(100);
+                                        s = 0;
+                                        fe->ops->read_status(fe, &s);
+                                        if (s & FE_HAS_LOCK) {
+                                                printk("DVB%i: Lock was lost, but regained by setting "
+                                                       "the tone. This may indicate your power supply "
+                                                       "is noisy/slightly incompatable with this DVB-S "
+                                                       "adapter\n", fe->dvb->num);
+                                                fepriv->state = FESTATE_TUNED;
+                                                continue;
+                                        }
+                                }
+#endif
+                                /* some other reason for losing the lock - start zigzagging */
                                 fepriv->state = FESTATE_ZIGZAG_FAST;
                                 fepriv->started_auto_step = fepriv->auto_step;
                                 check_wrapped = 0;
@@ -691,6 +711,7 @@ static int dvb_frontend_ioctl(struct inode *inode, struct file *file,
                         err = fe->ops->set_tone(fe, (fe_sec_tone_mode_t) parg);
                         fepriv->state = FESTATE_DISEQC;
                         fepriv->status = 0;
+                        fepriv->tone = (fe_sec_tone_mode_t) parg;
                 }
                 break;
 
@@ -893,6 +914,7 @@ int dvb_register_frontend(struct dvb_adapter* dvb,
         init_MUTEX (&fepriv->events.sem);
         fe->dvb = dvb;
         fepriv->inversion = INVERSION_OFF;
+        fepriv->tone = SEC_TONE_OFF;
 
         printk ("DVB: registering frontend %i (%s)...\n",
                 fe->dvb->num,