From patchwork Mon Feb 10 15:45:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Almeida X-Patchwork-Id: 61600 Received: from vger.kernel.org ([209.132.180.67]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1j1BEk-009nar-Ee; Mon, 10 Feb 2020 15:44:38 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727363AbgBJPqE (ORCPT + 1 other); Mon, 10 Feb 2020 10:46:04 -0500 Received: from mail-qt1-f195.google.com ([209.85.160.195]:46045 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726991AbgBJPqE (ORCPT ); Mon, 10 Feb 2020 10:46:04 -0500 Received: by mail-qt1-f195.google.com with SMTP id d9so5410213qte.12; Mon, 10 Feb 2020 07:46:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=qZzSV/Cejb8UpV/HQ8108YbaF0V/lqCH3FWdetQ8Pow=; b=bqERrv018aofLOYbac08392BfAcTQe7clJ9OzDV8jgahYWVeT/NaaOy4J0qiQoFYS8 hWw56aB3drHyzueud0IF/eHl4IkoW9XF918irUpRxhd1D30SPtzQxR9QK//nu6JnuBTB bk7Q+tPz7ZXtddEnVtgut02cdTOrxfQ+7NqJcGgmlRas2y7v5a/iwnj8aimT3OSEHmRr vQK8jVUuUqrC3Ama2VrTA5wfu2gZ6SNCze3g80sl5vlvBqZ+kBE/hvn1Ulju1/Yt9nPY TzKKecjCD3TkF9Ak+v09esvykMrddDwMSh5Mp+Fx27mRYuOG7w8Gu8iKWvlr98WqgreF /PtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=qZzSV/Cejb8UpV/HQ8108YbaF0V/lqCH3FWdetQ8Pow=; b=TKDAWIFOLBcPi4yGW7KQoD3p/BMbJ+5+RL0euRocxY0cE6cYwrietT/+9e0UBFOTn1 yAZjNBnMpiTatXQko1+72sFDu/XndshCU6+jWPBIPSHxMOSZSqW+f05UhAANVirpSmMD zvH5VYQsdVf8Q0oaWXE4pOa5GWT4hHhBoKS2I46KswZc6aOentR2tt1lDb5zOgBVdXKG 33ZDa+kPcpBQDMq3CiHZ386e4ie1cVejbZX5+ifiAe8Hnw3PFLiqCsnqRBHj/71BDDvr 9EDPNp/lxyrkHTHrbtkKRrIsR4gRjwEVc4bAtUjKtVeHhIyBiUVdgKQB9NY+9CTRi6p1 3XWg== X-Gm-Message-State: APjAAAUA7MqA7U0W76pmFDeg4Tn1Rrr4Rvb02Qu1zsCFax5NZT/woRHH rcUtH/wRu8cjkGVrItqQw4M= X-Google-Smtp-Source: APXvYqzPHFzNJtUhodxDnU6Bj7FldHbeHXQeKlnr9o6VdHUlF3LzXjc8bCXUcUrxDmM6665aYZqaNA== X-Received: by 2002:ac8:33f8:: with SMTP id d53mr10423304qtb.86.1581349562868; Mon, 10 Feb 2020 07:46:02 -0800 (PST) Received: from localhost.localdomain ([2804:14d:72b1:8920:a2ce:f815:f14d:bfac]) by smtp.gmail.com with ESMTPSA id c45sm350510qtd.43.2020.02.10.07.45.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Feb 2020 07:46:02 -0800 (PST) From: "Daniel W. S. Almeida" X-Google-Original-From: Daniel W. S. Almeida To: mchehab@kernel.org, sean@mess.org, tglx@linutronix.de, gregkh@linuxfoundation.org Cc: "Daniel W. S. Almeida" , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org Subject: [PATCH] media: dvb_dummy_fe.c: lose TS lock on bad snr Date: Mon, 10 Feb 2020 12:45:55 -0300 Message-Id: <20200210154555.156283-1-dwlsalmeida@gmail.com> X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: "Daniel W. S. Almeida" Periodically check the signal quality and eventually lose the lock if the quality is sub-par. A fake tuner can return a bad quality signal to the demod if the frequency is too far off from a valid frequency. Signed-off-by: Daniel W. S. Almeida --- drivers/media/dvb-frontends/dvb_dummy_fe.c | 149 ++++++++++++++++++++- 1 file changed, 144 insertions(+), 5 deletions(-) diff --git a/drivers/media/dvb-frontends/dvb_dummy_fe.c b/drivers/media/dvb-frontends/dvb_dummy_fe.c index 9ff1ebaa5e04..726c964a523d 100644 --- a/drivers/media/dvb-frontends/dvb_dummy_fe.c +++ b/drivers/media/dvb-frontends/dvb_dummy_fe.c @@ -9,24 +9,155 @@ #include #include #include +#include +#include #include #include "dvb_dummy_fe.h" +struct dvb_dummy_fe_cnr_to_qual_s { + /* attempt to use the same values as libdvbv5 */ + u32 modulation; + u32 fec; + u32 cnr_ok, cnr_good; +}; + +struct dvb_dummy_fe_cnr_to_qual_s dvb_c_cnr_2_qual[] = { + /* from libdvbv5 source code */ + { QAM_256, FEC_NONE, 34., 38.}, + { QAM_64, FEC_NONE, 30., 34.}, +}; + +struct dvb_dummy_fe_cnr_to_qual_s dvb_s_cnr_2_qual[] = { + /* from libdvbv5 source code */ + { QPSK, FEC_1_2, 7., 10.}, + + { QPSK, FEC_2_3, 9., 12.}, + { QPSK, FEC_3_4, 10., 13.}, + { QPSK, FEC_5_6, 11., 14.}, + + { QPSK, FEC_7_8, 12., 15.}, +}; + +struct dvb_dummy_fe_cnr_to_qual_s dvb_s2_cnr_2_qual[] = { + /* from libdvbv5 source code */ + { QPSK, FEC_1_2, 9., 12.}, + { QPSK, FEC_2_3, 11., 14.}, + { QPSK, FEC_3_4, 12., 15.}, + { QPSK, FEC_5_6, 12., 15.}, + { QPSK, FEC_8_9, 13., 16.}, + { QPSK, FEC_9_10, 13.5, 16.5}, + { PSK_8, FEC_2_3, 14.5, 17.5}, + { PSK_8, FEC_3_4, 16., 19.}, + { PSK_8, FEC_5_6, 17.5, 20.5}, + { PSK_8, FEC_8_9, 19., 22.}, +}; + +static struct dvb_dummy_fe_cnr_to_qual_s dvb_t_cnr_2_qual[] = { + /* from libdvbv5 source code */ + { QPSK, FEC_1_2, 4.1, 5.9}, + { QPSK, FEC_2_3, 6.1, 9.6}, + { QPSK, FEC_3_4, 7.2, 12.4}, + { QPSK, FEC_5_6, 8.5, 15.6}, + { QPSK, FEC_7_8, 9.2, 17.5}, + + { QAM_16, FEC_1_2, 9.8, 11.8}, + { QAM_16, FEC_2_3, 12.1, 15.3}, + { QAM_16, FEC_3_4, 13.4, 18.1}, + { QAM_16, FEC_5_6, 14.8, 21.3}, + { QAM_16, FEC_7_8, 15.7, 23.6}, + + { QAM_64, FEC_1_2, 14.0, 16.0}, + { QAM_64, FEC_2_3, 19.9, 25.4}, + { QAM_64, FEC_3_4, 24.9, 27.9}, + { QAM_64, FEC_5_6, 21.3, 23.3}, + { QAM_64, FEC_7_8, 22.0, 24.0}, +}; + +struct dvb_dummy_fe_config { + /* probability of losing the lock due to low snr */ + u8 drop_tslock_probability_on_low_snr; +}; + struct dvb_dummy_fe_state { struct dvb_frontend frontend; + struct dvb_dummy_fe_config config; + struct delayed_work poll_snr; + enum fe_status status; }; +void poll_snr_handler(struct work_struct *work) +{ + /* periodically check the signal quality and eventually + * lose the TS lock if it dips too low + */ + struct dvb_dummy_fe_state *state = + container_of(work, struct dvb_dummy_fe_state, poll_snr.work); + struct dtv_frontend_properties *c = &state->frontend.dtv_property_cache; + struct dvb_dummy_fe_cnr_to_qual_s *cnr2qual = NULL; + struct dvb_dummy_fe_config *config = &state->config; + u32 array_size = 0; + u16 snr = 0; + u32 i; + + if (!state->frontend.ops.tuner_ops.get_rf_strength) + return; + + state->frontend.ops.tuner_ops.get_rf_strength(&state->frontend, &snr); + + switch (c->delivery_system) { + case SYS_DVBT: + case SYS_DVBT2: + cnr2qual = dvb_t_cnr_2_qual; + array_size = ARRAY_SIZE(dvb_t_cnr_2_qual); + break; + + case SYS_DVBS: + cnr2qual = dvb_s_cnr_2_qual; + array_size = ARRAY_SIZE(dvb_s_cnr_2_qual); + break; + + case SYS_DVBS2: + cnr2qual = dvb_s2_cnr_2_qual; + array_size = ARRAY_SIZE(dvb_s2_cnr_2_qual); + break; + + case SYS_DVBC_ANNEX_A: + cnr2qual = dvb_c_cnr_2_qual; + array_size = ARRAY_SIZE(dvb_c_cnr_2_qual); + break; + + default: + pr_warn("%s: unsupported delivery system: %u\n", + __func__, + c->delivery_system); + break; + } + + for (i = 0; i <= array_size; i++) { + if (cnr2qual[i].modulation == c->modulation && + cnr2qual[i].fec == c->fec_inner) { + + if (snr < cnr2qual[i].cnr_ok) { + /* eventually lose the TS lock */ + if (prandom_u32_max(100) < + config->drop_tslock_probability_on_low_snr) + state->status = 0; + } + } + } + + schedule_delayed_work(&(state->poll_snr), msecs_to_jiffies(2000)); +} static int dvb_dummy_fe_read_status(struct dvb_frontend *fe, enum fe_status *status) { - *status = FE_HAS_SIGNAL - | FE_HAS_CARRIER - | FE_HAS_VITERBI - | FE_HAS_SYNC - | FE_HAS_LOCK; + + struct dvb_dummy_fe_state *state = fe->demodulator_priv; + + *status = state->status; return 0; } @@ -80,11 +211,18 @@ static int dvb_dummy_fe_set_frontend(struct dvb_frontend *fe) static int dvb_dummy_fe_sleep(struct dvb_frontend *fe) { + struct dvb_dummy_fe_state *state = fe->demodulator_priv; + + cancel_delayed_work_sync(&(state->poll_snr)); return 0; } static int dvb_dummy_fe_init(struct dvb_frontend *fe) { + struct dvb_dummy_fe_state *state = fe->demodulator_priv; + + INIT_DELAYED_WORK(&(state->poll_snr), &poll_snr_handler); + schedule_delayed_work(&(state->poll_snr), msecs_to_jiffies(2000)); return 0; } @@ -104,6 +242,7 @@ static void dvb_dummy_fe_release(struct dvb_frontend *fe) { struct dvb_dummy_fe_state *state = fe->demodulator_priv; + cancel_delayed_work_sync(&(state->poll_snr)); kfree(state); }