I am a twin and grew up in biological home. My mom's way of dealing with us was to take us to the skating rink and drop us off and my dad sat at the bar at nights. School work was secondary. In 3rd grade I never did my homework. I ended up doing all my homework in the principals office during my lunch hour after I'd eaten my lunch. They were nice to me and he'd even help if he saw I was struggling. I refused to read and they thought I was slow so I got put in the "late bird" section of reading. They made me mad and I was being defiant. My twin never graduated high school, but went on to get her Master's Degree. I have only a BA, but it took me longer than the standard four years. As for the roller skating, we ended up being national champions with all the effort we put in and continued and increased in skating over a period of 10+ years.
I'm saying homework isn't all that important if the concepts are learned. If he does some, but not all enjoy the night as a family. Sports, individual sports, with one-on-one attention is the best therapy we had. It focused attention, got rid of energy (and we had lots), and it had rewards for "good" effort, and something outside of school to look forward to. There were lots of kids down at the rink practicing that had problems and we all were in a controled environment, supervised, working toward a common goal, and supporting each other. There's not much going on in sports or PE for young boys much these days. Plus being active prepares a individual to be capable and fit for military service. We both also joined the USMC.
Just something from the other side of the coin that shows that we do survive. God Bless.