3 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/DocBook/media/dvb/dvbproperty.xml b/Documentation/DocBook/media/dvb/dvbproperty.xml
index 3bc8a61efe30..6ac803959a47 100644
--- a/Documentation/DocBook/media/dvb/dvbproperty.xml
+++ b/Documentation/DocBook/media/dvb/dvbproperty.xml
@@ -311,6 +311,8 @@ typedef enum fe_rolloff {
         ROLLOFF_20,
         ROLLOFF_25,
         ROLLOFF_AUTO,
+        ROLLOFF_15, /* DVB-C Annex A */
+        ROLLOFF_13, /* DVB-C Annex C */
 } fe_rolloff_t;
                 </programlisting>
                 </section>
@@ -778,8 +780,10 @@ typedef enum fe_hierarchy {
                         <listitem><para><link linkend="DTV-MODULATION"><constant>DTV_MODULATION</constant></link></para></listitem>
                         <listitem><para><link linkend="DTV-INVERSION"><constant>DTV_INVERSION</constant></link></para></listitem>
                         <listitem><para><link linkend="DTV-SYMBOL-RATE"><constant>DTV_SYMBOL_RATE</constant></link></para></listitem>
+                        <listitem><para><link linkend="DTV-ROLLOFF"><constant>DTV_ROLLOFF</constant></link></para></listitem>
                         <listitem><para><link linkend="DTV-INNER-FEC"><constant>DTV_INNER_FEC</constant></link></para></listitem>
                 </itemizedlist>
+                <para>The Rolloff of 0.15 (ROLLOFF_15) is assumed, as ITU-T J.83 Annex A is more common. For Annex C, rolloff should be 0.13 (ROLLOFF_13). All other values are invalid.</para>
         </section>
         <section id="dvbc-annex-b-params">
                 <title>DVB-C Annex B delivery system</title>
diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
index 2c0acdb4d811..c849455458ea 100644
--- a/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -876,6 +876,7 @@ static int dvb_frontend_clear_cache(struct dvb_frontend *fe)
         c->symbol_rate = QAM_AUTO;
         c->code_rate_HP = FEC_AUTO;
         c->code_rate_LP = FEC_AUTO;
+        c->rolloff = ROLLOFF_AUTO;
 
         c->isdbt_partial_reception = -1;
         c->isdbt_sb_mode = -1;
@@ -1030,6 +1031,7 @@ static void dtv_property_cache_init(struct dvb_frontend *fe,
                 break;
         case FE_QAM:
                 c->delivery_system = SYS_DVBC_ANNEX_AC;
+                c->rolloff = ROLLOFF_15; /* implied for Annex A */
                 break;
         case FE_OFDM:
                 c->delivery_system = SYS_DVBT;
diff --git a/include/linux/dvb/frontend.h b/include/linux/dvb/frontend.h
index 1b1094c35e4f..d9251df867b5 100644
--- a/include/linux/dvb/frontend.h
+++ b/include/linux/dvb/frontend.h
@@ -329,6 +329,8 @@ typedef enum fe_rolloff {
         ROLLOFF_20,
         ROLLOFF_25,
         ROLLOFF_AUTO,
+        ROLLOFF_15,     /* DVB-C Annex A */
+        ROLLOFF_13,     /* DVB-C Annex C */
 } fe_rolloff_t;
 
 typedef enum fe_delivery_system {