The rules for Wild Magic Surge are:
Immediately after you cast a sorcerer spell of 1st level or higher, the DM can have you roll a d20. If you roll a 1, roll on the Wild Magic Surge table to create a random magical effect.
And the rules for Tides of Chaos are:
Starting at 1st level, you can manipulate the forces of chance and chaos to gain advantage on one attack roll, ability check, or saving throw. Once you do so you must finish a long rest before you use this feature again.
Any time before you regain the use of this feature, the DM can have you roll on the Wild Magic Surge table immediately after you cast a sorcerer spell of 1st level or higher. You then regain the use of this feature.
How do these features interact with each other? I see two options:
They are the same roll. If the player has used their Tides of Chaos, any roll on the surge table will reset it.
They are different rolls. So only a roll specified as resetting Tides of Chaos would do so, and any other surge would not. By extension of this the DM could have the player get 2 surges on one spell, 1 for Wild Magic Surge and 1 to reset Tides of Chaos.
Our play group is not sure which is the correct option to use.