dvb-fe: Add a flag to indicate if DVBv5 stats is in use

Instead of trying every time to see if DVBv5 stats are available,
if version is equal or upper than 5.10, a call to FE_GET_PROPERTY
will fail only if a more permanent error happened (EFAULT, ENOMEM,
and similar errors).

A successful call to FE_GET_PROPERTY that returns all stat props
with len=0 means that the frontend doesn't implement any DVBv5
stats. So, if it fails once, it can be assumed that there's no
DVBv5 stats implemented for that frontend.

As a bonus, the logic now knows exactly if a measure came from
DVBv3 or from DVBv5 API.

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

diff --git a/lib/include/dvb-fe.h b/lib/include/dvb-fe.h
index 27b9aed..a588d8e 100644 (file)
--- a/lib/include/dvb-fe.h
+++ b/lib/include/dvb-fe.h
@@ -70,6 +70,7 @@ struct dvb_v5_fe_parms {
        unsigned                        verbose;
        struct dvb_frontend_info        info;
        uint32_t                        version;
+       int                             has_v5_stats;
        fe_delivery_system_t            current_sys;
        int                             num_systems;
        fe_delivery_system_t            systems[MAX_DELIVERY_SYSTEMS];

diff --git a/lib/libdvbv5/dvb-fe.c b/lib/libdvbv5/dvb-fe.c
index ec35922..07b40df 100644 (file)
--- a/lib/libdvbv5/dvb-fe.c
+++ b/lib/libdvbv5/dvb-fe.c
@@ -113,6 +113,11 @@ struct dvb_v5_fe_parms *dvb_fe_open2(int adapter, int frontend, unsigned verbose
        if (parms->version < 0x500)
                use_legacy_call = 1;
 
+       if (parms->version >= 0x50a)
+               parms->has_v5_stats = 1;
+       else
+               parms->has_v5_stats = 0;
+
        if (use_legacy_call || parms->version < 0x505) {
                parms->legacy_fe = 1;
                switch(parms->info.type) {
@@ -666,11 +671,54 @@ ret:
        return 0;
 }
 
+static struct dtv_stats *dvb_fe_store_stats(struct dvb_v5_fe_parms *parms,
+                             unsigned cmd,
+                             enum fecap_scale_params scale,
+                             unsigned layer,
+                             uint32_t value)
+{
+       int i;
+       for (i = 0; i < DTV_NUM_STATS_PROPS; i++) {
+               if (parms->stats.prop[i].cmd != cmd)
+                       continue;
+               parms->stats.prop[i].u.st.stat[layer].scale = scale;
+               parms->stats.prop[i].u.st.stat[layer].uvalue = value;
+               if (parms->stats.prop[i].u.st.len < layer + 1)
+                       parms->stats.prop[i].u.st.len = layer + 1;
+               return &parms->stats.prop[i].u.st.stat[layer];
+       }
+       dvb_logerr("%s not found on store", dvb_cmd_name(cmd));
+
+       return NULL;
+}
+
+static struct dtv_stats *dvb_fe_retrieve_v5_BER(struct dvb_v5_fe_parms *parms,
+                                               unsigned cmd, unsigned layer)
+{
+       struct dtv_stats *st_bec, *st_bc;
+       uint64_t ber64;
+
+       st_bec = dvb_fe_retrieve_stats_layer(parms, DTV_STAT_POST_BIT_ERROR_COUNT, layer);
+       if (!st_bec)
+               return NULL;
+
+       st_bc = dvb_fe_retrieve_stats_layer(parms, DTV_STAT_POST_TOTAL_BIT_COUNT, layer);
+       if (!st_bc || !st_bc->uvalue)
+               return NULL;
+
+       ber64 = (1E9 * st_bec->uvalue) / st_bc->uvalue;
+
+       return dvb_fe_store_stats(parms, DTV_BER, FE_SCALE_COUNTER, layer, ber64);
+}
+
 struct dtv_stats *dvb_fe_retrieve_stats_layer(struct dvb_v5_fe_parms *parms,
                                              unsigned cmd, unsigned layer)
 {
        int i;
 
+       if (cmd == DTV_BER && parms->has_v5_stats)
+               return dvb_fe_retrieve_v5_BER(parms, cmd, layer);
+
        for (i = 0; i < DTV_NUM_STATS_PROPS; i++) {
                if (parms->stats.prop[i].cmd != cmd)
                        continue;
@@ -711,27 +759,6 @@ int dvb_fe_retrieve_stats(struct dvb_v5_fe_parms *parms,
        return 0;
 }
 
-static int dvb_fe_store_stats(struct dvb_v5_fe_parms *parms,
-                             unsigned cmd,
-                             enum fecap_scale_params scale,
-                             unsigned layer,
-                             uint32_t value)
-{
-       int i;
-       for (i = 0; i < DTV_NUM_STATS_PROPS; i++) {
-               if (parms->stats.prop[i].cmd != cmd)
-                       continue;
-               parms->stats.prop[i].u.st.stat[layer].scale = scale;
-               parms->stats.prop[i].u.st.stat[layer].uvalue = value;
-               if (parms->stats.prop[i].u.st.len < layer + 1)
-                       parms->stats.prop[i].u.st.len = layer + 1;
-               return 0;
-       }
-       dvb_logerr("%s not found on store", dvb_cmd_name(cmd));
-
-       return EINVAL;
-}
-
 int dvb_fe_get_stats(struct dvb_v5_fe_parms *parms)
 {
        fe_status_t status = 0;
@@ -746,49 +773,31 @@ int dvb_fe_get_stats(struct dvb_v5_fe_parms *parms)
        }
        dvb_fe_store_stats(parms, DTV_STATUS, FE_SCALE_RELATIVE, 0, status);
 
-       if (parms->version >= 0x50a) {
+       if (parms->has_v5_stats) {
                struct dtv_properties props;
-               struct dtv_stats *st_bec, *st_bc;
 
                props.num = 6;
                props.props = parms->stats.prop;
 
                /* Do a DVBv5.10 stats call */
                if (ioctl(parms->fd, FE_GET_PROPERTY, &props) == -1)
-                       goto dvbv3_fallback;
+                       return errno;
 
-               /* If no stats i returned, fallback to the legacy API */
+               /*
+                * All props with len=0 mean that this device doesn't have any
+                * dvbv5 stats. Try the legacy stats instead.
+                */
                for (i = 0; i < props.num; i++)
                        if (parms->stats.prop[i].u.st.len)
                                break;
                if (i == props.num)
                        goto dvbv3_fallback;
-
-               /* Calculate and store BER */
-               for (i = 0; i < 4; i++) {
-                       uint64_t ber64;
-
-                       st_bec = dvb_fe_retrieve_stats_layer(parms, DTV_STAT_POST_BIT_ERROR_COUNT, i);
-                       if (!st_bec)
-                               goto no_ber;
-
-                       st_bc = dvb_fe_retrieve_stats_layer(parms, DTV_STAT_POST_TOTAL_BIT_COUNT, i);
-                       if (!st_bc || !st_bc->uvalue)
-                               goto no_ber;
-
-                       ber64 = (1E9 * st_bec->uvalue) / st_bc->uvalue;
-
-                       dvb_fe_store_stats(parms, DTV_BER, FE_SCALE_COUNTER, i, ber64);
-                       continue;
-no_ber:
-                       dvb_fe_store_stats(parms, DTV_BER, FE_SCALE_NOT_AVAILABLE, i, 0);
-               }
-
-               return 0;
        }
 
 dvbv3_fallback:
-       /* DVB v3 stats*/
+       /* DVB v3 stats */
+       parms->has_v5_stats = 0;
+
        if (ioctl(parms->fd, FE_READ_BER, &ber) == -1)
                scale = FE_SCALE_NOT_AVAILABLE;
        else