[mythtv] Bizzare repeating key behaviour

Matt skd5aner at gmail.com
Mon Sep 24 14:28:56 UTC 2007

On 9/24/07, Ian Goldberg <mythtv at paip.net> wrote:
> I've done a bunch of debugging of this myself, but now I need to ask for
> the collected wisdom of the list. ;-)
> I've been running MythTV for years.  I was happily running 0.16 (on a
> Debian sid box with two PVR-250s, running both the frontend and backend)
> for a long time.  But when I had to move from Zap2It to Schedule
> Direct, I needed to upgrade to 0.20.2.  Fine.  I did that, and
> everything was working fine (except for a very strage behaviour where,
> completely repeatably, around 36:40 into an hour-long recording, the
> recorded stream (as verified with mplayer) would go into "fast forward"
> for a few minutes, and then settle back down to normal; but that's not
> the problem I'm reporting right now).
> A chain of Debian sid dependencies (mythweb requires a recent php
> requires a recent apache requires a recent libc and all hell breaks
> loose) required a massive set of package upgrades on the sid box.
> Also, the latest ivtv driver requires a 2.6.22 kernel.  So I upgraded
> all of that.
> The "fast-forward" problem has gone away (with the new drivers?), and
> the backend now seems very stable.  But here's the problem I'm having
> with the frontend: keypresses (arrow keys, enter, escape) almost always
> "repeat" in the menu screens.  So it's really hard to choose things from
> the menus.  This happens whether I'm using lirc with irxevent, native
> lirc, pushing the key on my laptop with x2x, or if I push the key on the
> actual keyboard.
> Even more bizarrely, the debugging I've done so far seems to indicate
> that the "native lirc" issue and the "pressing a key" issue seem to be
> unrelated!
> Native lirc:
> If mythfrontend is *not* running, and I run irw, I see this if I push a
> key on the remote (and hold it down a brief time):
> 00000000000017e1 00 CH- hauppaugegrey
> 00000000000017e1 01 CH- hauppaugegrey
> If mythfrontend *is* running (and also irw), I see this:
> 00000000000017e1 00 CH- hauppaugegrey
> 00000000000017e1 00 CH- hauppaugegrey
> *even if I press CH- for a very short time*.  The lines also take
> noticeable time (up to 3 seconds) before they appear.  That is: I push
> CH-.  Three seconds later, both of those lines appear at once, and the
> selection on screen (in the "Select a recording to watch" screen, for
> example) moves two places.  In the "mythfrontend not running" case, the
> lines appear instantly.
> Pressing a key:
> I went as far as instrumenting libqt-mt.so (the version from debian
> sid).  In apps other than mythfrontend, it works fine.  But with
> mythfrontend, XNextEvent (called from src/kernel/qeventloop_x11.cpp:
> QEventLoop::processEvents, line 154) actually returns multiple KeyPress
> events:
> XNextEvent => 2
> Got XKeyPress event, time = 139090174
> Sending key event
> XNextEvent => 28
> XNextEvent => 3
> Got XKeyRelease event, time = 139091735
> Sending key event
> XNextEvent => 2
> Got XKeyPress event, time = 139091735
> Sending key event
> XNextEvent => 3
> Got XKeyRelease event, time = 139091736
> Sending key event
> XNextEvent => 28
> (that's from pressing a single key on the real attached keyboard).
> Note that there's a KeyPress (2), a KeyRelease(3), another KeyPress and
> another KeyRelease.
> This is completely replicable.  It happens almost every single time you
> press a key.  *But!* not when you're actually watching a program.  While
> you're watching TV, both the keypress and the lirc work just fine.  (And
> irw reverts to the normal "mythfrontend not running" behaviour.)
> Any clue what might be causing this?  Is there some weird state the
> mythfrontend menus (but not the playback) are putting the machine in?
> Thanks for any help you can give.  As you can see, I'm happy to do any
> diagnostics you'd like, up to and including kernel hacking.  ;-)
> Thanks,
>   - Ian

I know this isn't going to help, but if it makes you feel any better,
I have to be very careful with the "escape" key on my remote.  It
seems like it's almost always gets interpreted as a double-key press.
However, if I use my wireless keyboard, it doesn't seem to do that
(unless I obviously hold the key down).  I have seen other people
report similiar behavior, but as far as I know, none of the devs
experience the issue and no one else has been able to successfully
track it down in order to give the devs something to go on.


More information about the mythtv-dev mailing list