From: Michael Hennerich <[email protected]> For transfer counts > 255 bytes, the Blackfin TWI peripheral sets the data transfer counter DCNT to 0xFF indicating unlimited transfers. It then uses a flag iface->manual_stop to manually issue the STOP condition once the required amount of bytes are received.
It seems that if the STOP condition is issued with a full receive fifo, the TWI logic constantly drives the SDA/SCL lines low thus locking the bus. So to make sure this doesn't happen, consume the fifo first. Signed-off-by: Michael Hennerich <[email protected]> Signed-off-by: Mike Frysinger <[email protected]> --- drivers/i2c/busses/i2c-bfin-twi.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c index 52b545a..5ed6c2f 100644 --- a/drivers/i2c/busses/i2c-bfin-twi.c +++ b/drivers/i2c/busses/i2c-bfin-twi.c @@ -131,6 +131,10 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface, iface->transPtr++; iface->readNum--; } else if (iface->manual_stop) { + /* Avoid possible bus stall - + * Flush FIFO before issuing the STOP condition + */ + read_RCV_DATA16(iface); write_MASTER_CTL(iface, read_MASTER_CTL(iface) | STOP); } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT && -- 1.7.5.rc3 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
