If a start bit is detected, then reset the receive buffer counter to 0.
This ensures that no stale data is in the buffer if a message is
broken off midstream due to e.g. a Low Drive condition and then
retransmitted.
The only Rx interrupts we need to listen to are RX_REGISTER_FULL (i.e.
a valid byte was received) and RX_START_BIT_DETECTED (i.e. a new
message starts and we need to reset the counter).
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # for v4.15 and up
---
drivers/media/platform/tegra-cec/tegra_cec.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/drivers/media/platform/tegra-cec/tegra_cec.c b/drivers/media/platform/tegra-cec/tegra_cec.c
index 92f93a880015..aba488cd0e64 100644
--- a/drivers/media/platform/tegra-cec/tegra_cec.c
+++ b/drivers/media/platform/tegra-cec/tegra_cec.c
@@ -172,16 +172,13 @@ static irqreturn_t tegra_cec_irq_handler(int irq, void *data)
}
}
- if (status & (TEGRA_CEC_INT_STAT_RX_REGISTER_OVERRUN |
- TEGRA_CEC_INT_STAT_RX_BUS_ANOMALY_DETECTED |
- TEGRA_CEC_INT_STAT_RX_START_BIT_DETECTED |
- TEGRA_CEC_INT_STAT_RX_BUS_ERROR_DETECTED)) {
+ if (status & TEGRA_CEC_INT_STAT_RX_START_BIT_DETECTED) {
cec_write(cec, TEGRA_CEC_INT_STAT,
- (TEGRA_CEC_INT_STAT_RX_REGISTER_OVERRUN |
- TEGRA_CEC_INT_STAT_RX_BUS_ANOMALY_DETECTED |
- TEGRA_CEC_INT_STAT_RX_START_BIT_DETECTED |
- TEGRA_CEC_INT_STAT_RX_BUS_ERROR_DETECTED));
- } else if (status & TEGRA_CEC_INT_STAT_RX_REGISTER_FULL) {
+ TEGRA_CEC_INT_STAT_RX_START_BIT_DETECTED);
+ cec->rx_done = false;
+ cec->rx_buf_cnt = 0;
+ }
+ if (status & TEGRA_CEC_INT_STAT_RX_REGISTER_FULL) {
u32 v;
cec_write(cec, TEGRA_CEC_INT_STAT,
@@ -255,7 +252,7 @@ static int tegra_cec_adap_enable(struct cec_adapter *adap, bool enable)
TEGRA_CEC_INT_MASK_TX_BUS_ANOMALY_DETECTED |
TEGRA_CEC_INT_MASK_TX_FRAME_TRANSMITTED |
TEGRA_CEC_INT_MASK_RX_REGISTER_FULL |
- TEGRA_CEC_INT_MASK_RX_REGISTER_OVERRUN);
+ TEGRA_CEC_INT_MASK_RX_START_BIT_DETECTED);
cec_write(cec, TEGRA_CEC_HW_CONTROL, TEGRA_CEC_HWCTRL_TX_RX_MODE);
return 0;
--
2.14.1
