use strict;
use Data::Dumper;

while (<DATA>)
{
  chomp;
  my @rec;
  # was - foreach (split /"(.*,.*)"|,/) ...
  foreach (split /"((?:\\"|.)*?)"|,/) { push @rec, $_ if $_ }
  print Dumper(\@rec);
}

__DATA__
1,"Hello, world",This is good,2
121212,"Simpson, Bart",Springfield,"Roger"
121212,"2\" tape, \"white",springfield,"Roger"
121212,"Simpson \", Bart",Springfield,"Roger"