Between Linux and Anime

So there are a good number of threads for zypper/yast hanging up in the middle of various actions, but none were relevant to my particular problem, so throwing this out into the googlespace for the next person who might end up facing my problem.

The Symptoms: Yast Software Manager and Zypper would randomly freeze and stay frozen apparently indefinitely – at least for hours. The freeze occurs seemingly randomly in the midst of any action that may require downloading – including refreshing repositories and actually downloading packages/updates.

What is happening: Staring at zypper output on -vv I began noticing that it always hangs up when trying to download something from download.opensuse.org. It doesn’t do so consistently: most of the time the download happens, but sometimes it doesn’t and it freezes forever – but always when attempting to download from download.opensuse.org. With some research I found out that download.opensuse.org isn’t actually a centralized download repository but uses something called mirrorbrain that transparently redirects you to a chosen download mirror. So it would appear that one of those mirrors were having trouble with me – perhaps my IP is somehow blacklisted by that server. What’s confounding is that it doesn’t seem to be able to flag an error or at least timeout so I can be served another mirror or simply retry – it just goes on staying stuck forever.

Solution: With the hypothesis that one of the mirrors is somehow rejecting me in this inexplicable way, a direct solution would be to simply find a mirror that is happy with me, and force zypper/yast to use it. For core OpenSUSE packages (distribution and update), a list of mirros is available here. For the repositories at http://download.opensuse.org/repositories/ though, I couldn’t find a mirror list. Instead, I discovered that when you open the listing of packages on a browser, for eg here, you can click on ‘details’ next to any package and that shows a list of mirrors you can get the package from.

So armed with this knowledge, I simply went through all my enabled repositories, looked for all repositories that have download.opensuse.org as source, and replaced the url with that of a specific mirror. After that zypper and yast operated without problems.

Of course, this is a non-optimal set up, so after a while you might consider switching back to download.opensuse.org and see if the problem has gone away.

Or not.

Recent versions of Chromium (and, presumably, Google Chrome) appear to be capable of differentiating between input from a touch screen, and input from a mouse. The problem is, on Linux, you’ll often find the capability a counter-productive one, since chromium sometimes outright IGNORES all touch input, rendering chromium utterly inoperable with a touchscreen. Mouse and touchpad operates chromium okay? Touchscreen operates other applications okay but you can’t so much as click a link on Chromium? You’re probably experiencing what I’m talking about.

There’s a report here, but it doesn’t seem to be going anywhere at the moment. Apparently Ubuntu carries a patch that tries to fix this, and I’m not sure how well it works, but at least on OpenSUSE we appear to be on our own. Fortunately, it’s possible to workaround, based on a suggestion in the comments.

First, on the terminal, type

xinput list

You should get a listing that looks like

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Atmel Atmel maXTouch Digitizer            id=10   [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad                id=13   [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Power Button                              id=8    [slave  keyboard (3)]
    ↳ Lenovo EasyCamera                         id=9    [slave  keyboard (3)]
    ↳ Ideapad extra buttons                     id=11   [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=12   [slave  keyboard (3)]

You need to look for the name of your touch screen hardware. In the above case, that is “Atmel Atmel maXTouch Digitizer”. Note the id number for the hardware on the right, 10 in the above case.

What you need to do is pass this id as a parameter to Chromium/Chrome. Like so:

chromium --touch-devices=10

Replace 10 of course with the id of your device. Launched this way, touch input should actually work reasonably on Chromium. In particular – you can switch tabs with touch, touch links to visit them, and even touch-scroll.

Of course, it’s a little tedious to do this every time you want to start Chromium. Fortunately, it’s not hard to put it all in a script. Like so:

#!/bin/bash
SCREEN=`xinput list | awk '/maXTouch/ { gsub(".*id=",""); print $1 }'`
exec chromium --touch-devices=$SCREEN

Of course, you’ll need to change ‘maXTouch’ above to a suitable identifier for your particular device, but running the script should start Chromium in touch-usable state. If you want, you can even modify your application menu entry to call this script instead of the Chromium binary directly.

UPDATE

It seems the above doesn’t quite work anymore on recent versions of Chromium. On my own box I’ve found that I now need to use the id of the parent item – ie “Virtual Core Pointer”, id=2 in the listing above. The rest of the procedure is basically the same, and if you use the script above you’ll need to make a minor adjustment to look for Virtual Core Pointer instead.

If you find, like I did for my box, that the id for Virtual Core Pointer stays the same all the time, instead of making a script you could just add the command line flag to the Chromium default settings config file. On OpenSUSE 13.2 this is at /etc/default/chromium, though I hear it can also be at /etc/chromium/default on some platforms. Simply add the following to the file:

CHROMIUM_FLAGS="--touch-devices=2"

This is cleaner and would probably also live across version updates :)

It’s surprisingly hard to get the Playstation 2 emulator PCSX2 working if you’re running a 64-bit linux system, even though they’re cross platform and release linux binaries/sources first hand. The primary roadblock seems to be that the thing assumes a 32bit environment, and will refuse to start if it doesn’t find some 32-bit libs. Anyway, I got this working twice, both times quite bumpily, and decided it was high time this got written into a post for archival.

Credits by the way to this video which put me on the right track.

First, we gotta get PCSX2. This can either be downloaded from the site linked above, or, on OpenSUSE, can be obtained in packaged form from Pacman’s Games repo (mirror for 13.1 here).

Then we gotta grab the 32-bit libs that are needed. If you installed it with dependencies off the Pacman repo this may be taken care of for you (I’m not 100% sure), but in any case what you need to do is to pull out the Yast software installation interface and do a search for ‘wx’. This should get you a list like the following:

Now make sure each of those installed items are installed as 32-bit versions. Basically, click each of them, then click the ‘Versions’ tab, and make sure the ‘i586’ version is selected. Else select it, and apply at the end. For other distros, the gist I guess is to make sure you have 32bit/i586 versions of libwx and wxWidgets packages installed.

That should net you the required 32-bit libs, and you can give the pcsx2 executable a whirl at this point and hope for the best. In my case, I had one more hurdle before PCSX2 would run – the thing seems to be looking for the libwx libs in the wrong path. Fortunately it’s possible to tell it manually where to load the libs from by setting the LD_LIBRARY_PATH environment variable. This can be set right before running PCSX2 like so:

LD_LIBRARY_PATH=/usr/lib/wx-2.8-stl/ pcsx2

‘/usr/lib/wx-2.8-stl‘ is where the 32-bit libwx .so’s are on my system. This may vary for different distros, but it shouldn’t be overly hard to locate. Setting LD_LIBRARY_PATH appropriately allowed me to actually launch the PCSX2 UI, where configuring plugins, BIOS, etc may then proceed.

Running on integrated Intel graphics (I’m on a Lenovo Yoga 11s, Haswell version), the GS plugin that let me run games quite performantly is GSdx, configured to use “OpenGL (Hardware)”. Note that in Linuxland, open source drivers for higher-grade graphic cards (think Nvidia, ATI) don’t tend to perform well for graphic-heavy applications, so you’ll want to either switch to the proprietary drivers for those cards (if they exist and can be obtained), or to fall back to using the integrated Intel graphics chip, which tends to have good open source drivers.

I also had trouble with sound initially, which I was able to get around by first disabling Pulseaudio. Then, using the Spu2-X SPU plugin, configured to

Module: PortAudio
PortAudio API: ALSA
Synchronization mode: TimeStretch
Latency: 50

I was able to get pretty good sound for my games. Note that with ALSA it’s possible to get into a funny situation where ALSA selects a non-working sound card as default sound card – causing you to have no sound since the SPU plugin appears to be hardwired to use ALSA’s default card. This can in turn be remedied using the solution documented in my previous blog post.

Edit: it looks like one does not actually need to disable Pulse. If you can’t get sound on Pulse, try making the updated ~/.asoundrc file documented in my previous blog post. Using that I am able to get PCSX2 on PortAudio to coexist with all my other sound applications.

Whew! And that should cover everything. At least, that’s everything I know :) Perhaps it might help someone struggling with it as I was, but for now, I’m just happy to be able to play Persona 4 on Linux ^^

So yeah I’m still alive. Just on hiatus thanks to loads of irl stuff, as usual. I suppose the saving grace of this blog’s livelihood is that I’ll always have practical motivations to come here and drop a fixit I discover – since it works as my own personal documentation as well. I still want to write anime of course, I just need to find the time.

Anyway, shoutout to Idyllictux for his help with this one.

So OpenSUSE comes built with Pulseaudio nowadays, and for the most part it’s well set up and “just works”. There are obscure cases where it doesn’t quite perform though, for me anyway, cases like recording sound via the mic input, and playing games on PCSX2. Wonderfully enough, it’s fairly trivial on OpenSUSE to kill Pulse and fall back on Alsa. Having done that though, I found myself in a peculiar pickle where Alsa appeared to have found 2 sound cards and picked the non-working one for default. This, too, is not normally a big problem, since for KDE stuff you could just configure phonon in one place, and for stuff like smplayer you could just direct it manually to use the right sound card. Sometimes though, like in PCSX2’s case, things appear to be hardcoded to use the default soundcard, leaving you with non-working sound.

I tried Googling briefly for how I could tell Alsa to disable/forget a sound card, or to switch its default sound card, and found that there, apparently, used to be a tool called ‘asoundconf’ that lets you deal with such things. However, I wasn’t able to find nor install this on my system. Fortunately, Mr Idyllictux demonstrated there was another way:

First, list your sound cards with:

aplay -l

You should get an output that looks like:

**** List of PLAYBACK Hardware Devices ****
card 0: MID [HDA Intel MID], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: MID [HDA Intel MID], device 7: HDMI 1 [HDMI 1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: MID [HDA Intel MID], device 8: HDMI 2 [HDMI 2]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: PCH [HDA Intel PCH], device 0: CX20756 Analog [CX20756 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0


Look for the number of the sound card you want to make default. Then, create (or edit) the file ~/.asoundrc with the following:

pcm.!default {
type hw
card 1
}

Replacing the ‘1’ in ‘card 1’ with the number of the sound card you want to be default. Save it and restart your session, and Alsa should now use the card as default.

Edit: The above will work, but will also create the iffy (and sickeningly familiar) problem of every sound application hogging the sound card (so you can’t have two applications playing sound at the same time). Copying and trial-and-error-ing blobs of config from Idyllictux‘s setup, I was able to discover an optimal .asoundrc as follows:

pcm.!default {
type hw
card 1
}

pcm.!default {
type plug
slave.pcm "dmixer"
}

pcm.dmixer {
type dmix
ipc_key 1024
slave {
pcm "hw:1,0"
period_time 0
buffer_time 0
period_size 2048
buffer_size 32768
rate 44100
}
bindings {
0 0
1 1
}
}

Replace ‘Card 1’ with your card as per above. This config (which also works with pulse enabled) actually lets everything I have co-exist sound-wise (including PCSX2 on PortAudio, and smplayer using ‘alsa’ for audio). The only minor downside is that if you run this with pulse, you’ll lose the per-app volume control feature, presumably because we’re bypassing pulse’s software mixer.

This was the last link I needed to get PCSX2 fully working on my 64-bit Linux system. I’ll try and find time to document that one too, hopefully in the near future.