Ubuntu
platform-api package

  1. Bug #1620553
  2. Comment #1

Comment 1 for bug 1620553

Revision history for this message
Andrea Bernabei (faenil) wrote : Re: [Krillin] Taps are delayed by 1-2seconds, although gestures are not. Keyboard is thus unusable

I think I know that it could be!
I think it's the vibration handler!

After inputting the passcode in the greeter, unity8 prints the following lines *after* the 2 secs delay:
org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

And as noted in the bug description, one of the sympthoms was that vibration stopped working.

I think what happened is that the vibrator handler crashed, and on every tap that requires vibration the system is waiting some timeout for the vibrator to reply to the DBus call before timing out.

Those calls are probably synchronous, hence blocking the UI until a reply is received (do we really have to block the UI to vibrate?). But since the other end is probably dead, the phone stalls until the NoReply answer is received, and only then the UI thread gets back in control again.