Hi Hans,
> > > > > @@ -58,6 +58,8 @@ struct viai2c {
> > > > > u16 tcr;
> > > > > int irq;
> > > > > u16 cmd_status;
> > > > > + ktime_t ti;
> > > > > + ktime_t to;
> > > > don't these need some arbitration?
> > > >
> > > I don't think it needs to be arbitration.
> > > the controllers are independent of each other,
> > > each access is locked using __i2c_lock_bus_helper().
> > > Am I missing something?
> > no, it's fine, it's me who missed that. Do you mind writing a
> > comment?
>
>
> ok, will add a comment like below:
> + /*
> + * During each byte access, the host performs clock stretching.
> + * In this case, the thread may be interrupted by preemption,
> + * resulting in a long stretching time.
> + *
> + * However, some touchpad can only tolerate host clock stretching
> + * of no more than 200 ms. We reduce the impact of this through
> + * a retransmission mechanism.
> + *
> + * Since __i2c_lock_bus_helper() is used to ensure that the
> + * current access will not be interrupted by the other access,
> + * We don't need to worry about arbitration anymore.
> + *
> + */
> + local_irq_disable();
> + i2c->to = ktime_get();
ack!
Andi
