There are maintainers for each subsystem. For example, linux/drivers/media is maintained by Mauro Carvalho Chehab. When you have a patch, you submit it to the l

There are maintainers for each subsystem. For example, linux/drivers/media is maintained by Mauro Carvalho Chehab. When you have a patch, you submit it to the linux-media mailing list and it's vetted there. If Mauro thinks it's good, then he'll submit it to Linus as part of a large merge package. For the two patches I submitted, it took two months to get in the kernel.