Dennis,

My apologies for the late reply.  I needed some time to rethink my position.

After I posted my reply talking about an I2C "backpack" for a simple
two-line LCD display I realized that even just monitoring the LCD's "busy"
line and subsequently feed it (more) data would require a level of
intelligence of the I2C driver that I could/should not expect from it.

In short, I realized I got a bit ahead of myself.   :-|

>>The only question is if that has already been implemented, or if I need
>>to/can do it myself.
>
> https://www.kernel.org/doc/html/v4.14/driver-api/i2c.html
> """
> Note about combined messages: Some I2C controllers can only send
> one message per transfer, plus something called combined message or
> write-then-read.
...
> int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg * msgs, int
> num)
[snip]

Thanks.   You (again) gave me lots of stuff to look at.   :-)

And as you described it an actually working-as-atomic sequence of multiple
(mixes of) read/write sequences is a bit of the luck-of-the-draw.  IOW: It
/might/ work in one implementation, but doesn't need to in another.  I can't
say I like that ....

> And just to be annoying:
> https://www.raspberrypi.org/forums/viewtopic.php?t=135928

Did you really /have/ to do that (being annoying) ? :-)

But yes, thats (multi-threading) also something to be looked at.

Regards,
Rudy Wieser

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