1 files changed, 38 insertions, 0 deletions

diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
index ce1de403e99e..7e9cd7921314 100644
--- a/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -993,6 +993,42 @@ int is_legacy_delivery_system(fe_delivery_system_t s)
         return 0;
 }
 
+/* Synchronise the legacy tuning parameters into the cache, so that demodulator
+ * drivers can use a single set_frontend tuning function, regardless of whether
+ * it's being used for the legacy or new API, reducing code and complexity.
+ */
+void dtv_property_cache_sync(struct dvb_frontend *fe, struct dvb_frontend_parameters *p)
+{
+        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+
+        c->frequency = p->frequency;
+        c->inversion = p->inversion;
+
+        switch (fe->ops.info.type) {
+        case FE_QPSK:
+                c->symbol_rate = p->u.qpsk.symbol_rate;
+                c->fec_inner = p->u.qpsk.fec_inner;
+                break;
+        case FE_QAM:
+                c->symbol_rate = p->u.qam.symbol_rate;
+                c->fec_inner = p->u.qam.fec_inner;
+                c->modulation = p->u.qam.modulation;
+                break;
+        case FE_OFDM:
+                c->bandwidth = p->u.ofdm.bandwidth;
+                c->code_rate_HP = p->u.ofdm.code_rate_HP;
+                c->code_rate_LP = p->u.ofdm.code_rate_LP;
+                c->modulation = p->u.ofdm.constellation;
+                c->transmission_mode = p->u.ofdm.transmission_mode;
+                c->guard_interval = p->u.ofdm.guard_interval;
+                c->hierarchy = p->u.ofdm.hierarchy_information;
+                break;
+        case FE_ATSC:
+                c->modulation = p->u.vsb.modulation;
+                break;
+        }
+}
+
 int dtv_property_cache_submit(struct dvb_frontend *fe)
 {
 
@@ -1548,6 +1584,8 @@ static int dvb_frontend_ioctl_legacy(struct inode *inode, struct file *file,
         case FE_SET_FRONTEND: {
                 struct dvb_frontend_tune_settings fetunesettings;
 
+                dtv_property_cache_sync(fe, &fepriv->parameters);
+
                 if(fe->dtv_property_cache.state == DTV_TUNE) {
                         if (dvb_frontend_check_parameters(fe, &fepriv->parameters) < 0) {
                                 err = -EINVAL;