Em Thu, 11 Jun 2020 13:57:13 +0200 Marc Gonzalez <marc.w.gonzalez@xxxxxxx> escreveu: > Some demodulators (e.g. si2168) are able to scan for DVB-T and DVB-T2 > signals concurrently. Use SYS_DVBT_AUTO for this purpose. > --- > This is a Request For Comments from media maintainers and users :-) Sorry for taking so long to answer... Somehow, this one got stuck in the middle of the pile of patches. I don't think this patch is needed. The same also happens with DVB-S/S2 cards: when some of those are set to the second gen, it may report both 1st and 2nd gen channels. The main issue is actually how to report that a scanned channel is DVB-T during a DVB-T2 scan: the driver should likely identify those and set the properties accordingly. > > One issue: suppose DVB Project publishes DVB-T3 in a few years. > Today's demods might handle T/T2, but they won't handle T3, while users > may expect SYS_DVBT_AUTO to mean "all DVB-T standards". > > Therefore, perhaps the delsys name should be explicit, > like SYS_DVBT_DVBT2 or SYS_DVBT_1_2. > Then if/when DVB_T3 appears, we can add SYS_DVBT_1_2_3 ??? > > Or maybe use the FE_CAN_2G_MODULATION and hypothetical FE_CAN_3G_MODULATION > > Or maybe, with several standards having a v2 and possibly v3 in the future, > delivery system might move to a bitmask approach? (API issues though) > > Reference to related implementation: > https://patchwork.kernel.org/patch/10744999/ > --- > drivers/media/dvb-frontends/si2168.c | 2 +- > include/uapi/linux/dvb/frontend.h | 3 +++ > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c > index 14b93a7d3358..8578b8917955 100644 > --- a/drivers/media/dvb-frontends/si2168.c > +++ b/drivers/media/dvb-frontends/si2168.c > @@ -624,7 +624,7 @@ static int si2168_deselect(struct i2c_mux_core *muxc, u32 chan) > } > > static const struct dvb_frontend_ops si2168_ops = { > - .delsys = {SYS_DVBT, SYS_DVBT2, SYS_DVBC_ANNEX_A}, > + .delsys = {SYS_DVBT, SYS_DVBT2, SYS_DVBT_AUTO, SYS_DVBC_ANNEX_A}, > .info = { > .name = "Silicon Labs Si2168", > .frequency_min_hz = 48 * MHz, > diff --git a/include/uapi/linux/dvb/frontend.h b/include/uapi/linux/dvb/frontend.h > index 4f9b4551c534..3a6348748041 100644 > --- a/include/uapi/linux/dvb/frontend.h > +++ b/include/uapi/linux/dvb/frontend.h > @@ -600,6 +600,8 @@ enum fe_rolloff { > * Terrestrial TV: DVB-T > * @SYS_DVBT2: > * Terrestrial TV: DVB-T2 > + * @SYS_DVBT_AUTO: > + * Terrestrial TV: Autodetect DVB-T gen > * @SYS_ISDBT: > * Terrestrial TV: ISDB-T > * @SYS_ATSC: > @@ -645,6 +647,7 @@ enum fe_delivery_system { > SYS_DVBT2, > SYS_TURBO, > SYS_DVBC_ANNEX_C, > + SYS_DVBT_AUTO, > }; > > /* backward compatibility definitions for delivery systems */ Thanks, Mauro
