From: Hans Verkuil <hverkuil@xs4all.nl> To: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org, Hans Verkuil <hans.verkuil@cisco.com> Subject: [PATCHv2 6/6] cec-gpio: select correct Signal Free Time Date: Fri, 5 Oct 2018 15:37:45 +0200 [thread overview] Message-ID: <20181005133745.8593-7-hverkuil@xs4all.nl> (raw) In-Reply-To: <20181005133745.8593-1-hverkuil@xs4all.nl> From: Hans Verkuil <hans.verkuil@cisco.com> If a receive is in progress or starts before the transmit has a chance, then lower the Signal Free Time of the upcoming transmit to no more than CEC_SIGNAL_FREE_TIME_NEW_INITIATOR. This is per the specification requirements. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> --- drivers/media/cec/cec-pin.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/media/cec/cec-pin.c b/drivers/media/cec/cec-pin.c index 6e311424f0dc..635db8e70ead 100644 --- a/drivers/media/cec/cec-pin.c +++ b/drivers/media/cec/cec-pin.c @@ -935,6 +935,17 @@ static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer) /* Start bit, switch to receive state */ pin->ts = ts; pin->state = CEC_ST_RX_START_BIT_LOW; + /* + * If a transmit is pending, then that transmit should + * use a signal free time of no more than + * CEC_SIGNAL_FREE_TIME_NEW_INITIATOR since it will + * have a new initiator due to the receive that is now + * starting. + */ + if (pin->tx_msg.len && pin->tx_signal_free_time > + CEC_SIGNAL_FREE_TIME_NEW_INITIATOR) + pin->tx_signal_free_time = + CEC_SIGNAL_FREE_TIME_NEW_INITIATOR; break; } if (ktime_to_ns(pin->ts) == 0) @@ -1157,6 +1168,15 @@ static int cec_pin_adap_transmit(struct cec_adapter *adap, u8 attempts, { struct cec_pin *pin = adap->pin; + /* + * If a receive is in progress, then this transmit should use + * a signal free time of max CEC_SIGNAL_FREE_TIME_NEW_INITIATOR + * since when it starts transmitting it will have a new initiator. + */ + if (pin->state != CEC_ST_IDLE && + signal_free_time > CEC_SIGNAL_FREE_TIME_NEW_INITIATOR) + signal_free_time = CEC_SIGNAL_FREE_TIME_NEW_INITIATOR; + pin->tx_signal_free_time = signal_free_time; pin->tx_extra_bytes = 0; pin->tx_msg = *msg; -- 2.18.0
WARNING: multiple messages have this Message-ID (diff)
From: Hans Verkuil <hverkuil@xs4all.nl> To: linux-media@vger.kernel.org Cc: Hans Verkuil <hans.verkuil@cisco.com>, dri-devel@lists.freedesktop.org Subject: [PATCHv2 6/6] cec-gpio: select correct Signal Free Time Date: Fri, 5 Oct 2018 15:37:45 +0200 [thread overview] Message-ID: <20181005133745.8593-7-hverkuil@xs4all.nl> (raw) In-Reply-To: <20181005133745.8593-1-hverkuil@xs4all.nl> From: Hans Verkuil <hans.verkuil@cisco.com> If a receive is in progress or starts before the transmit has a chance, then lower the Signal Free Time of the upcoming transmit to no more than CEC_SIGNAL_FREE_TIME_NEW_INITIATOR. This is per the specification requirements. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> --- drivers/media/cec/cec-pin.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/media/cec/cec-pin.c b/drivers/media/cec/cec-pin.c index 6e311424f0dc..635db8e70ead 100644 --- a/drivers/media/cec/cec-pin.c +++ b/drivers/media/cec/cec-pin.c @@ -935,6 +935,17 @@ static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer) /* Start bit, switch to receive state */ pin->ts = ts; pin->state = CEC_ST_RX_START_BIT_LOW; + /* + * If a transmit is pending, then that transmit should + * use a signal free time of no more than + * CEC_SIGNAL_FREE_TIME_NEW_INITIATOR since it will + * have a new initiator due to the receive that is now + * starting. + */ + if (pin->tx_msg.len && pin->tx_signal_free_time > + CEC_SIGNAL_FREE_TIME_NEW_INITIATOR) + pin->tx_signal_free_time = + CEC_SIGNAL_FREE_TIME_NEW_INITIATOR; break; } if (ktime_to_ns(pin->ts) == 0) @@ -1157,6 +1168,15 @@ static int cec_pin_adap_transmit(struct cec_adapter *adap, u8 attempts, { struct cec_pin *pin = adap->pin; + /* + * If a receive is in progress, then this transmit should use + * a signal free time of max CEC_SIGNAL_FREE_TIME_NEW_INITIATOR + * since when it starts transmitting it will have a new initiator. + */ + if (pin->state != CEC_ST_IDLE && + signal_free_time > CEC_SIGNAL_FREE_TIME_NEW_INITIATOR) + signal_free_time = CEC_SIGNAL_FREE_TIME_NEW_INITIATOR; + pin->tx_signal_free_time = signal_free_time; pin->tx_extra_bytes = 0; pin->tx_msg = *msg; -- 2.18.0 _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2018-10-05 20:36 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-10-05 13:37 [PATCHv2 0/6] cec/adv/cec-gpio: fixes and new status flags Hans Verkuil 2018-10-05 13:37 ` Hans Verkuil 2018-10-05 13:37 ` [PATCHv2 1/6] cec-core.rst: improve cec_transmit_done documentation Hans Verkuil 2018-10-05 13:37 ` Hans Verkuil 2018-10-05 13:37 ` [PATCHv2 2/6] cec: add new tx/rx status bits to detect aborts/timeouts Hans Verkuil 2018-10-05 13:37 ` Hans Verkuil 2018-10-05 13:37 ` [PATCHv2 3/6] adv7604: when the EDID is cleared, unconfigure CEC as well Hans Verkuil 2018-10-05 13:37 ` Hans Verkuil 2018-10-05 13:37 ` [PATCHv2 4/6] adv7842: " Hans Verkuil 2018-10-05 13:37 ` Hans Verkuil 2018-10-05 13:37 ` [PATCHv2 5/6] cec: fix the Signal Free Time calculation Hans Verkuil 2018-10-05 13:37 ` Hans Verkuil 2018-10-05 13:37 ` Hans Verkuil [this message] 2018-10-05 13:37 ` [PATCHv2 6/6] cec-gpio: select correct Signal Free Time Hans Verkuil
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