Hi Andi:
Thank you for your comments.
Andi Shyti <andi.shyti@xxxxxxxxxx> 於 2024年10月24日 週四 下午6:04寫道：
>
> Hi Tyrone,
>
> ...
>
> > + /*
> > + * Previously, the 7-bit address was stored and being converted to
> > + * the address of event in the following call to npcm_i2c_master_start_xmit().
>
> Do we care how it was done previously? I think this is not a
> useful information as the code readers will se the code the way
> it is now, not the way it was done "previously".
>
Yes, it's not a useful information anymore.
> (there is a related comment at the end)
>
> > + * Since there are cases that the i2c_recover_bus() gets called at the
> > + * early stage of npcm_i2c_master_xfer(), the address of event is stored
> > + * and then used in the i2c_recover_bus().
>
> I could rephrase this sentence to something like:
>
> /*
> * Store the address early in a global position to ensure it is
> * accessible for a potential call to i2c_recover_bus().
> */
Understood. Thank you for your help on this.
>
> > + */
> > + bus->dest_addr = i2c_8bit_addr_from_msg(msg0);
> > +
> > /*
> > * Check the BER (bus error) state, when ber_state is true, it means that the module
> > * detects the bus error which is caused by some factor like that the electricity
> > @@ -2165,6 +2175,15 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> > * bus is busy.
> > */
> > if (bus_busy || bus->ber_state) {
> > + /*
> > + * Since the transfer might be a read operation, remove the I2C_M_RD flag
> > + * from the bus->dest_addr for the i2c_recover_bus() call later.
> > + *
> > + * The i2c_recover_bus() uses the address in a write direction to recover
> > + * the i2c bus if some error condition occurs.
> > + */
> > + bus->dest_addr &= ~I2C_M_RD;
> > +
> > iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
> > npcm_i2c_reset(bus);
> > i2c_recover_bus(adap);
> > @@ -2172,7 +2191,6 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> > }
> >
> > npcm_i2c_init_params(bus);
> > - bus->dest_addr = slave_addr;
>
> We can now get rid of slave_addr. It's just used in
> npcm_i2c_master_start_xmit(). Right?
Yes, slave_addr is just used as the link
https://github.com/torvalds/linux/blob/master/drivers/i2c/busses/i2c-npcm7xx.c#L2182
suggests with this patch.
>
> Andi
>
> > bus->msgs = msgs;
> > bus->msgs_num = num;
> > bus->cmd_err = 0;
> > --
> > 2.34.1
> >
Thank you.
Regards,
Tyrone
