On Wed, Apr 21, 2021 at 11:54:43AM +0200, Johan Hovold wrote: > The infamous low_latency behaviour of tty_flip_buffer_push(), which > meant that data could be pushed to the line discipline immediately > instead of being deferred to a work queue, was finally removed in 2014. > > Since then there's no need for drivers to keep hacks to temporarily drop > the port lock during receive processing but this pattern has been > reproduced in later added drivers nonetheless. > > Note that several of these workarounds were added by a series posted in > 2013, which ended up being merged despite having completely nonsensical > commit messages. As it turned out, it was just the RT patch set which > effectively enabled the low_latency flag for serial drivers that did not > handle it. > > There's of course nothing wrong releasing the port lock before calling > tty_flip_buffer_push(), and some drivers still do after this series, but > let's get rid of the completely unnecessary unlock-and-reacquire > pattern. Many thanks for cleaning up this old crud, all now applied. greg k-h
