Hi Andi:
Thank you for your feedback.
Your comments will be addressed.
Andi Shyti <andi.shyti@xxxxxxxxxx> 於 2024年9月26日 週四 上午4:24寫道：
>
> 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
> >
Have a nice day.
Regards,
Tyrone
