From your description of the the tear it would seem the best way to make a lasting repair would be to remove the awning material and either replace it or have a shop like the ones that make truck cargo tarps resew the material or cut out the old section and resew the channel cord back in. If the tear were farther out (like I had on my class A) I would use tape.
Jake my sidekick (yellow Lab)
2017 RAM 2500 CC 4X4 Cummins Diesel
2016 Flagstaff 26 FKWS
AF&AM of Idaho