touch-packages team mailing list archive

[Seth Forshee <seth.forshee+lp@xxxxxxxxxxxxx>]

The powerd main thread only ever checks fb_state with the mutex locked,
and the monitor thread only ever changes it with the mutex locked. The
main thread also only calls pthread_cond_wait() *after* finding fb_state
!= FB_AWAKE *without any intervening unlock of the mutex.* So the
scenario you describe is impossible. If the monitor thread changes
fb_state to FB_AWAKE before the main thread locks the mutex, it will see
fb_state == FB_AWAKE on the first loop iteration and never call
pthread_cond_wait(). If the main thread locks the mutex before the
monitor thread changes the state then the monitor thread cannot change
the state until pthread_cond_wait() releases the mutex, then the
subsequent pthread_cond_signal() call will awaken the main thread.

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Touch seeded packages, which is subscribed to powerd in Ubuntu.
https://bugs.launchpad.net/bugs/1450017

Title:
  Sometimes resuming leaves only a black lit screen, no unity8

Status in powerd package in Ubuntu:
  New
Status in unity8 package in Ubuntu:
  New

Bug description:
  Sometimes when I turn my dogfooding mako device on (running stable
  channel), I see a back lighted screen, but no unity8.  It stays like
  that indefinitely, and I just have to hard-reset.

  I haven't noticed any obvious correlations to the behavior.  It just
  happens.

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