Hi Tyrone,
...
> diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
> index 2d034503d8bc..68f3d47323ab 100644
> --- a/drivers/i2c/busses/i2c-npcm7xx.c
> +++ b/drivers/i2c/busses/i2c-npcm7xx.c
> @@ -2132,19 +2132,12 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> }
> }
>
> - /*
> - * Adaptive TimeOut: estimated time in usec + 100% margin:
> - * 2: double the timeout for clock stretching case
> - * 9: bits per transaction (including the ack/nack)
> - */
> - timeout_usec = (2 * 9 * USEC_PER_SEC / bus->bus_freq) * (2 + nread + nwrite);
> - timeout = max_t(unsigned long, bus->adap.timeout, usecs_to_jiffies(timeout_usec));
> if (nwrite >= 32 * 1024 || nread >= 32 * 1024) {
> dev_err(bus->dev, "i2c%d buffer too big\n", bus->num);
> return -EINVAL;
> }
>
> - time_left = jiffies + timeout + 1;
> + time_left = jiffies + bus->adap.timeout / bus->adap.retries + 1;
> do {
> /*
> * we must clear slave address immediately when the bus is not
> @@ -2183,6 +2176,14 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> if (npcm_i2c_master_start_xmit(bus, slave_addr, nwrite, nread,
> write_data, read_data, read_PEC,
> read_block)) {
> + /*
> + * Adaptive TimeOut: estimated time in usec + 100% margin:
> + * 2: double the timeout for clock stretching case
> + * 9: bits per transaction (including the ack/nack)
> + */
> + timeout_usec = (2 * 9 * USEC_PER_SEC / bus->bus_freq) * (2 + nread + nwrite);
> + timeout = max_t(unsigned long, bus->adap.timeout / bus->adap.retries,
> + usecs_to_jiffies(timeout_usec));
> time_left = wait_for_completion_timeout(&bus->cmd_complete,
> timeout);
>
> @@ -2308,7 +2309,7 @@ static int npcm_i2c_probe_bus(struct platform_device *pdev)
> adap = &bus->adap;
> adap->owner = THIS_MODULE;
> adap->retries = 3;
> - adap->timeout = msecs_to_jiffies(35);
> + adap->timeout = 2 * HZ;
Same here, I need some good description of why timeout is set to
2 seconds. If the datasheet says 35ms, I do not exclude that
someone in the future will send a patch saying "we don't need to
wait 2 seconds, wait 35ms as per datasheet".
Thanks,
Andi
> adap->algo = &npcm_i2c_algo;
> adap->quirks = &npcm_i2c_quirks;
> adap->algo_data = bus;
> --
> 2.34.1
>
