Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e113d65a authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
Browse files

media: tegra-cec: reset rx_buf_cnt when start bit detected 



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: default avatarHans Verkuil <hans.verkuil@cisco.com>
Cc: <stable@vger.kernel.org>      # for v4.15 and up
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 2fe4c22c

drivers/media/platform/tegra-cec/tegra_cec.c

+7 −10
Original line number Diff line number Diff line
@@ -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;