Re: [PATCH 2/2] i2c: smbus: Send alert notifications to all devices if source not found

[Guenter Roeck]

On 7/29/24 11:36, Wolfram Sang wrote:
> > I looked into the code again. The sequence is (or is supposed to be):
> >
> > 1st loop:
> > 	if (!alert_pending)
> > 		break;
> > 	smbus_do_alert()
> > 	if (failed at same address)
> > 		smbus_do_alert_force()
> >
> > 2nd loop:
> > 	if (!alert_pending)
> > 		break;
> > 	smbus_do_alert()
> > 	if (failed at same address)
> > 		break;
> >
> > I think what you are suggesting is
> ...
>
> What I am suggesting is more like this:
>
> 1st loop:
>
>   	smbus_do_alert()
> 	//impossible to have same address on first run, so go to 2nd loop
>
> 2nd loop:
>
>   	smbus_do_alert()
>   	if (failed at same address)
>   		smbus_do_alert_force()
> 		break;
>
> As I understand it, your sequence is missing "my" 1st loop with the
> invalid address, so you will end up having 3 loops altogether?
>
> The code I am suggesting is bascially yours without the retries
> variable:
>
> 	status = device_for_each_child(&ara->adapter->dev, &data,
> 				       smbus_do_alert);
> 	if (data.addr == prev_addr && status != -EBUSY) {
> 		device_for_each_child(&ara->adapter->dev, &data,
> 				      smbus_do_alert_force);
> 		break;
> 	}
> 	prev_addr = data.addr;
>
> Makes sense or am I missing something?

Yes, that should work and is indeed simpler. You are correct, the
additional loop should not be necessary since smbus_do_alert_force()
should already call all connected drivers and hopefully clear
the alert condition on those.

Thanks,
Guenter