Re: [PATCH 3/4] auxdisplay: charlcd: fix x/y address commands

From: Robert Abel
Date: Mon Feb 26 2018 - 17:43:43 EST


On 26 Feb 2018 17:49, Miguel Ojeda wrote:
> On a general note, the code seems a bit convoluted for what it does,
> specially without the comment written in the commit message :-) Isn't
> it simpler to use a tiny array in the stack and put the numbers to be
> converted instead of modifying the input sequence and dancing with
> pointers?

That's what I felt at first, too. If we can drop the backwards
compatibility of repeated xy commands, the whole affair gets much
easier, but will unfortunately break existing use.

Ex. ^[[Lx004y002x006; --> x6y2, because repeats of x would just
overwrite earlier values. That's what the while loop allowed in the
first place.

I suspect the while loop to parse was just a clever way of parsing y
followed by x and x followed by y using the same code and the
overwriting behavior is actually an unaccounted-for side-effect.

Regards,

Robert