Alan Cox wrote: > Benjamin Herrenschmidt wrote: >> Seems that we are in interrupt, doing hvc_poll, which does >> tty_flip_buffer_push > >Which means that someone has tty->low_latency set and is calling >tty_flip_buffer_push in an IRQ. That has never been allowed or safe, and >now it hurts ;) > >/** > * tty_flip_buffer_push - terminal > * @tty: tty to push > * > * Queue a push of the terminal flip buffers to the line discipline. >This > * function must not be called from IRQ context if tty->low_latency >is set * > * In the event of the queue being busy for flipping the work will be > * held off and retried later. > * > * Locking: tty buffer lock. Driver locks in low latency mode. > */ > > >That comment has been there for some years in varying formats >
I actually was preparing a patch for this problem after I had encountered the a deadlock due to this. That is in the first patch. I then found and made a few more cleanups, although I might have reordered the rest. The history for setting low_latency is in the changelog of the first patch.. milton _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
