diff mbox series

cec-pin: fix off-by-one SFT check

Message ID 4f1e5106-d97d-b51f-9a96-2c38b26898b8@xs4all.nl (mailing list archive)
State New, archived
Headers show
Series cec-pin: fix off-by-one SFT check | expand

Commit Message

Hans Verkuil Aug. 11, 2021, 11:36 a.m. UTC 
The CEC pin framework has to wait for the CEC bus to be idle for the
requested Signal Free Time before it can start a transmit.

However, the check for that was off by one, so transmits would start one
bit period (2.4ms) too late.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
---
diff mbox series

Patch

diff --git a/drivers/media/cec/core/cec-pin.c b/drivers/media/cec/core/cec-pin.c
index f006bd8eec63..195576a53c82 100644
--- a/drivers/media/cec/core/cec-pin.c
+++ b/drivers/media/cec/core/cec-pin.c
@@ -957,7 +957,7 @@  static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer)
 			 * so we can kick off the pending transmit.
 			 */
 			delta = ktime_us_delta(ts, pin->ts);
-			if (delta / CEC_TIM_DATA_BIT_TOTAL >
+			if (delta / CEC_TIM_DATA_BIT_TOTAL >=
 			    pin->tx_signal_free_time) {
 				pin->tx_nacked = false;
 				if (tx_custom_start(pin))
@@ -968,7 +968,7 @@  static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer)
 				cec_pin_low(pin);
 				break;
 			}
-			if (delta / CEC_TIM_DATA_BIT_TOTAL >
+			if (delta / CEC_TIM_DATA_BIT_TOTAL >=
 			    pin->tx_signal_free_time - 1)
 				pin->state = CEC_ST_TX_WAIT;
 			break;