The GPL (v2) sets no specific delay but it also sets no specific deadline by which the code must be released after a request has been made.
While the delays these companies are making are pretty lame and obviously go against the spirit of the GPLv2, releasing code 120 days after product release (or more importantly, from the first specific request for code from a customer who bought the product) is not clearly in violation, from a legal standpoint.
Are you a lawyer? Because in the past the advice I've been given is that the absence of a deadline on a requirement does not imply the ability to impose your own choice of deadline. 120 days is clearly far more than would be reasonably required to provide the code.
it also sets no specific deadline by which the code must be released after a request has been made
I imagine that 120 days would not be seen as reasonable in terms of a license/contract when the words are "upon request." Hyper-legalisms like "no specific deadline" are irrelevant.
It's pretty simple when it comes down to it - the copyright holders are the only people who can take action, and the fact that there is no "grace period" simply means that they are illegally distributing the binaries.
While the delays these companies are making are pretty lame and obviously go against the spirit of the GPLv2, releasing code 120 days after product release (or more importantly, from the first specific request for code from a customer who bought the product) is not clearly in violation, from a legal standpoint.