[mythtv-users] mythfrontend suddenly became very slow to read lirc input

[Hika van den Hoven]

Hoi Marc,

Monday, September 21, 2015, 4:42:03 PM, you wrote:

> On Sun, Sep 20, 2015 at 11:08:51PM -0700, Marc MERLIN wrote:
>> (cc on replies appreciated, thanks)
>> 
>> I have an admittedly outdated mythtv 0.25.0+fixes.20120622 which has
>> been working well enough for 3 years, but it just started being super
>> slow responding to remote keys at the main menus.
>> Something like 3-5 seconds for each key down press to be registered.
>> 
>> Once I'm playing a video, remote keypresses are instant, so mythfrontend
>> passes keys fine when playing video but not when displaying its menu
>> options.
>> If I use the plugged in keyboard up/down from the keyboard instantly
>> goes to prev/next menu option.
>> 
>> If I use vnc to connect to my X server running mythfrontend, I can also
>> instantly move to next/prev menu options.
>> 
>> But if I go back to the remote, it takes seconds. If I push down 3
>> times, it goes down 3 times, just takes seconds for it to happen (all 3
>> at once).
>> 
>> lirc seems to work fine:
>> myth:~# irw
>> 000000008001006c 00 KEY_DOWN devinput
>> 0000000080010067 00 KEY_UP devinput
>> It shows that the keys are instantly received and output to clients, be
>> it irw or mythfrontend.
>> 
>> So it seems that mythfrontend has decided to just hang before reading
>> from lirc, or read from lirc and wait a while before doing anything with
>> input commands, but only when displaying its menus. Once it plays
>> videos, then it's fine.
>> 
>> Kernel is 4.1.3 on ubuntu lucid (yes, that's old too, but I don't
>> upgrade things that work and need to keep working, and I'm not even
>> going to go through the list of things that ubuntu changed/broke for me
>> in new versions).
>> 
>> Considering I changed nothing with my config that I can think of, I'm a
>> bit at a loss of how to debug this further.
>> 
>> Any idea what to try next?

> Well, this is embarassing.
> The same exact problem happened to me on 25 Nov 2012 and I found the
> reply to my own post after looking harder.
>  
> But: upgrading libqt from 4.7 to 4.8 breaks in the subtle way I
> described. I had just installed vlc, and that upgraded libqt which then
> broke mythfrontend.

> Still, the weirdest bug I've ever seen...

> To make sure I don't get bitten again:
> dpkggrep libqt4 | awk '{print $1}' | while read pkg; do echo "$pkg
> hold" | dpkg --set-selections; done

> Marc

That must be something more than just QT. I see no problems with QT
4.8.6 on any of my frontends! Do you perchance also run an old lirc?
Or anything else old! It could be it interacts bad with your very new
kernel!

Tot mails,
  Hika                            mailto:hikavdh at gmail.com

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Zonder leven is er geen hoop
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