Comment 1 for bug 1868113

Not sure if I understand that ticket correctly - which 5.4-rc7 was used?
Was is directly from upstream?
And why is still a RC kernel in use - 5.4 is released since quite some time?

Well, if only commit "net/mlx5e: RX, Always prefer Linear SKB configuration" is needed, then we are done, since it's already in the Ubuntu focal kernel since quite some time:

focal-clean$ git log --oneline --grep "net/mlx5e: RX, Always prefer Linear SKB configuration"
5ffd81943d7a net/mlx5e: RX, Always prefer Linear SKB configuration
focal-clean$ git tag --contains 5ffd81943d7a
Ubuntu-5.4-5.4.0-10.13
Ubuntu-5.4-5.4.0-11.14
Ubuntu-5.4-5.4.0-12.15
Ubuntu-5.4-5.4.0-13.16
Ubuntu-5.4-5.4.0-14.17
Ubuntu-5.4.0-15.18
Ubuntu-5.4.0-16.19
Ubuntu-5.4.0-17.20
Ubuntu-5.4.0-17.21
Ubuntu-5.4.0-18.22
Ubuntu-5.4.0-8.11
Ubuntu-5.4.0-9.12

Looks to me that you can simply move to the current Ubuntu focal kernel (ideally the one from proposed) and proceed with testing from there ...