/* * The DRM_*WAIT*_UNTIL macros are replacements for the Linux * wait_event* macros. Like DRM_SPIN_WAIT_ON, they add an interlock, * and so may require some changes to the surrounding code. They have * a different return value convention from DRM_SPIN_WAIT_ON and a * different return value convention from cv_*wait*. * * The untimed DRM_*WAIT*_UNTIL macros return * * . -EINTR/-ERESTART if interrupted by a signal, or * . zero if the condition evaluated * * The timed DRM_*TIMED_WAIT*_UNTIL macros return * * . -EINTR/-ERESTART if interrupted by a signal, * . 0 if the condition was false after the timeout, * . 1 if the condition was true just after the timeout, or * . the number of ticks remaining if the condition was true before the * timeout. * * Contrast DRM_SPIN_WAIT_ON which returns -EINTR/-ERESTART on signal, * -EBUSY on timeout, and zero on success; and cv_*wait*, which return * -EINTR/-ERESTART on signal, -EWOULDBLOCK on timeout, and zero on * success. * * XXX In retrospect, giving the timed and untimed macros a different * return convention from one another to match Linux may have been a * bad idea. All of this inconsistent timeout return convention logic * has been a consistent source of bugs. */