Stephan Vierkant's questions

I'm having problems with using Composer. composer diagnose gives this result:

Checking platform settings: OK
Checking git settings: OK
Checking http connectivity to packagist: FAIL
[Composer\Downloader\TransportException] curl error 61 while downloading http://repo.packagist.org/packages.json: Unrecognized content encoding type. libcurl understands identity content encodings.
Checking https connectivity to packagist: FAIL
[Composer\Downloader\TransportException] curl error 61 while downloading https://repo.packagist.org/packages.json: Unrecognized content encoding type. libcurl understands identity content encodings.
// ...
Checking composer version: OK
Composer version: 2.1.8
PHP version: 8.0.11
PHP binary path: /usr/bin/php8.0
OpenSSL version: OpenSSL 1.1.1f  31 Mar 2020
cURL version: 7.68.0 libz  ssl OpenSSL/1.0.2n
zip: extension present, unzip present, 7-Zip not available

I've tried to find out what the problem is, but I can't find out. Two thinks that looks weird to me:

1. There is no version number after libz.
2. OpenSSL 1.1.1f is installed, but curl is using OpenSSL/1.0.2n.

On another server (with almost the same configuration, where composer works fine) I see some other versions are being used:

OpenSSL version: OpenSSL 1.1.1f  31 Mar 2020
cURL version: 7.68.0 libz 1.2.11 ssl OpenSSL/1.1.1f

This are the versions numbers of my server with issues:

$ curl --version
curl 7.68.0 (x86_64-pc-linux-gnu) libcurl/7.68.0 OpenSSL/1.0.2n
Release-Date: 2020-01-08
Protocols: dict file ftp ftps gopher http https imap imaps pop3 pop3s rtsp smb smbs smtp smtps telnet tftp 
Features: AsynchDNS HTTPS-proxy IPv6 Largefile NTLM NTLM_WB SSL TLS-SRP UnixSockets

While the other (working) server has other protocols and features as well:

$ curl --version
curl 7.68.0 (x86_64-pc-linux-gnu) libcurl/7.68.0 OpenSSL/1.1.1f zlib/1.2.11 brotli/1.0.9 libidn2/2.3.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0 librtmp/2.3
Release-Date: 2020-01-08
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtmp rtsp scp sftp smb smbs smtp smtps telnet tftp 
Features: AsynchDNS brotli GSS-API HTTP2 HTTPS-proxy IDN IPv6 Kerberos Largefile libz NTLM NTLM_WB PSL SPNEGO SSL TLS-SRP UnixSockets

How can I fix this problem with composer not connecting to packagist?

I'm using Ubuntu 20.04.3 LTS.

I've got a Dell Thunderbolt dock (TB16) on my Dell XPS 13 notebook. When I use the ethernet connection on my dock, local websites (192.168.1.x, like web interfaces of my printer, Pi-Hole, ZTE H369A router) don't work properly because of corrupted data. Printing on my Samsung network printer (M2070) doesn't work; it prints just a couple of random characters instead.

When I set the speed of the wired connection to 10 or 100 Mb/s it works fine, but when I set Link negotiation to Automatic or Ignore or when I set Speed to 1 or 10Gb/s, I get corrupted data.

When I go to a local webpage, I get Uncaught SyntaxError: Invalid or unexpected token or Uncaught SyntaxError: Unexpected token ']' in the console. The response (in this case jquery-1.7.2.min.js) is malformed:

unction(FHH@4@F��C��|9S�7E4!�@�ˏ
��o��p��6<R�'?�~���x
6uM��k����gk.length>1&&!R[a]?f.unique(e):e,(this.length>1||N.test(d))&&M.test(a)&&(e=e.reverse());return this.pushStack(e,a,P.call(arguments).join(","))}}),f.extend({filter:function(a,b,c){c&&(a=":not("+a+")");return b.length===1?f.find.matchesSelector(b[0],a)?[b[0]]:[]:f.find.matches(a,b)},dir:function(a,c,d){var e=[],g=a[c];while(g&&g.nodeType!==9&&(d===b||g.nodeType!==1||!f(g).is(d)))g.nodeType===1&&e.push(g),g=g[c];return e},nth:function(a,b,c,d){b=b||1;var e=0;for(;a;a=a[c])if(a.nodeType===1&&++e===b)break;return a},sibling:function(a,b){var c=[];for(;a;a=a.nextSibling)a.nodeType===1&&a!==b&&c.push(a);return c}});var V="abbr|article|aside|audio|bdi|canvas|data|datalist|details|figcaption|figure|footer|header|hgroup|mark|meter|nav|output|progress|section|summary|time|video",W=/ jQuery\d+="(?:\d+|null)"/g,X=/^\s+/,Y=/<(?!area|br|col|embed|hr|img|input|link|meta|param)(([\w:]+)[^>]*)\/>/ig,Z=/<([\w:]+)/,$=/<tbody/i,_=/<|&#?\w+;/,ba=/<(?:script|style)/i,bb=/<(?:script|object|embed|option|style)/i,bc=new RegExp("<(?:"+V+")[\\s/>]","i"),bd=/checked\s*(?:[^=]|=\s*.checked.)/i,be=/\/(java|ecma)script/i,bf=/^\s*<!(?:\[CDATA\[|\-\-)/,bg={option:[1,"<select multiple='multiple'>","</select>"],legend:[1,"<fieldset>","</fieldset>"],thead:[1,"<table>","</table>"],tr:[2,"<table><tbody>","</tbody></table>"],td:[3,"<table><tbody><tr>","</tr></tbody></table>"],col:[2,"<table><tbody></tbody><colgroup>","</colgroup></table>"],area:[1,"<map>","</map>"],_default:[0,"",""]},bh=U(c);bg.optgroup=bg.option,bg.tbody=bg.tfoot=bg.colgroup=bg.caption=bg.thead,bg.th=bg.td,f.support.htmlSerialize||(bg._default=[1,"div<div>","</div>"]),f.fn.extend({text:function(a){return f.access(this,function(a){return a===b?f.text(this):this.empty().append((this[0]&&this[0].ownerDocument||c).createTextNode(a))},null,a,arguments.length)},wrapAll:function(a){if(f.isFunction(a))return this.each(function(b){f(this).wrapAll(a.call(this,b))});if(this[0]){var b=f(a,this[0].ownerDocument).eq(0).clone(!0);this[0].parentNode&&b.insertBefore(this[0]),b.map(function(){var a=this;while(a.firstChild&&a.firstChild.nodeType===1)a=a.firstChild;return a}).append(this)}return this},wrapInner:function(a){if(f.isFunction(a))return this.each(function(b){f(this).wrapInner(a.call(this,b))});return this.each(function(){var b=f(this),c=b.contents();c.length?c.wrapAll(a):b.append(a)})},wrap:function(a){var b=f.isFunction(a);return this.each(function(c){f(this).wrapAll(b?a.call(this,c):a)})},unwrap:function(){return this.parent().each(function(){f.nodeName(this,"body")||f(this).replaceWith(this.childNodes)}).end()},append:function(){return this.domManip(arguments,!0,function(a){this.nodeType===1&&this.appendChild(a)})},prepend:function(){return this.domManip(arguments,!0,function(a){this.nodeType===1&&this.insertBefore(a,this.firstChild)})},before:function(){if(this[0]&&this[0].parentNode)return this.domManip(arguments,!1,function(a){this.parentNode.insertBefore(a,this)});if(arguments.length){var a=f
function(a){return f.dir(a,"nextSibling")},prevAll:function(FHH@4@F��C��|9S�7E4!�@�ˏ
��o��p��6<R�'?�~���x

Other (non-local) websites are working fine and using another ethernet adapter (or Wi-Fi) is working fine too. Even my router interface (192.168.1.254) is working fine when using a reverse proxy (router.mypersonaldomain.example). That might be because my internet connection is just 65 Mb/s, but I'm not sure if that's the reason.

I'm having this problem for a couple of years now and updating the firmware drivers or Ubuntu didn't and I'm curious what the exact problem is. The problem also exists when using a Ubuntu Live USB and also on both Chrome and Firefox.

How do I find out what the exact problem is? Before I'm looking into solutions, I want to know what the technical issue is.

I'd like to use Konqueror because I found a comparison between different file managers that stated that Konqueror one of the most customizable file managers. However, in my case the configuration or extensions modal is almost empty. When I start Konqueror using the CLI, I see these error messages:

org.kde.konqueror: Unable to load the "File Management" configuration module org.kde.konqueror: Unable to load the "Web Browsing" configuration module

Unfortunately, I can't find anything related to this error message.

I installed Konqueror using apt install konqueror, which installed version 5.0.97. I'm using Kubuntu 18.10 with Plasma 5.13.5.

Any idea how I can configure Konqueror? Why are those modals (almost) empty?

Screenshots:

I'm trying to get rid of all my old videotapes using a USB grabber (Fushicai USBTV007 Video Grabber [EasyCAP]). When I use VLC or Open Broadcaster Software I can get the video stream from /dev/video2.

With an old Hi8 camera (Hitachi VM-H630E) it works fine, but with my VHS player (Thomson VTH6210) it just gives a black screen and no sound. I know the player is fine because on a television it just works.

I've tried to change all settings I could find (using the monkey testing industry standard), but it makes no difference at all.

How can I get this working?

When I boot up my computer when there is another network adaptor active (Ethernet adaptor in my USB-C dock, or even a virtual network created by Docker), my WLAN adaptor stays 'unclaimed':

$ sudo lshw -C network
*-network UNCLAIMED       
   description: Network controller
   product: QCA6174 802.11ac Wireless Network Adapter
   vendor: Qualcomm Atheros
   physical id: 0
   bus info: pci@0000:3a:00.0
   version: 32
   width: 64 bits
   clock: 33MHz
   capabilities: pm msi pciexpress cap_list
   configuration: latency=0

*-network
   description: Ethernet interface
   physical id: 2
   logical name: enxd481d722ec02
   serial: d4:81:d7:22:ec:02
   size: 1Gbit/s                                                                                                                                                                                                                                                                                                                                                                     
   capacity: 1Gbit/s                                                                                                                                                                                                                                                                                                                                                                 
   capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation                                                                                                                                                                                                                                                                               
   configuration: autonegotiation=on broadcast=yes driver=r8152 driverversion=v1.08.6 duplex=full ip=192.103.1.122 link=yes multicast=yes port=MII speed=1Gbit/s                                                                                                                                                                                                                       resources: memory:dc000000-dc1fffff

After disconnecting my Ethernet adaptor and removing docker, my wlan is working fine. When I plugin my Ethernet adaptor after connecting to WiFi, it's also working fine.

$ lsusb
Bus 004 Device 003: ID 0bda:8153 Realtek Semiconductor Corp. 
Bus 004 Device 002: ID 05e3:0617 Genesys Logic, Inc. 
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 003: ID 0835:2a01 Action Star Enterprise Co., Ltd 
Bus 003 Device 002: ID 05e3:0610 Genesys Logic, Inc. 4-port hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 002: ID 0424:5742 Standard Microsystems Corp. 
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 006: ID 0c45:670c Microdia 
Bus 001 Device 005: ID 04f3:20d0 Elan Microelectronics Corp. 
Bus 001 Device 003: ID 0cf3:e300 Atheros Communications, Inc. 
Bus 001 Device 004: ID 138a:0091 Validity Sensors, Inc. 
Bus 001 Device 002: ID 0424:2742 Standard Microsystems Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

$ rfkill list all
0: hci0: Bluetooth
        Soft blocked: no
        Hard blocked: no

Full debug info is here at Pastebin

Why does my wireless adaptor stays unclaimed and how can I fix this?

I'm using Kubuntu 17.04 on a Dell XPS 13 9360 (problem already existed while using 16.10).

I'm using Ubuntu 16.10 with Unity and KDE Plasma installed. I installed Ubuntu 16.04 (from the Dell recovery image of my XPS 13 9360 Developer Edition), upgraded to 16.10 and installed kubuntu-desktop.

On my login screen (both sddm and lightdm), my bluetooth mouse is working. But after logging in with Plasma, my bluetooth device stops working when Bluedevil is installed. The bluetooth applet says bluetooth is off-line and the checkbox is grayed out.

The power on command of bluetoothctl gives

Failed to set power on: org.bluez.Error.Failed

After many many hours of experimenting, I found out bluedevil is part of the problem. After sudo apt remove bluedevil and a reboot, everything is working fine (apart from the missing bluetooth applet of course).

Here is a tail of my syslog, just after logging in using KDE Plasma:

Apr  1 22:41:27 stephan-XPS-13-9360 bluetoothd[950]: Starting SDP server
Apr  1 22:41:28 stephan-XPS-13-9360 bluetoothd[950]: Bluetooth management interface 1.13 initialized
Apr  1 22:41:28 stephan-XPS-13-9360 bluetoothd[950]: Failed to obtain handles for "Service Changed" characteristic
Apr  1 22:41:28 stephan-XPS-13-9360 bluetoothd[950]: Sap driver initialization failed.
Apr  1 22:41:28 stephan-XPS-13-9360 bluetoothd[950]: sap-server: Operation not permitted (1)
Apr  1 22:41:28 stephan-XPS-13-9360 NetworkManager[942]: <info>  [1491079288.2767] Loaded device plugin: NMBluezManager (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-device-plugin-bluetooth.so)
Apr  1 22:41:28 stephan-XPS-13-9360 NetworkManager[942]: <info>  [1491079288.2915] bluez: use BlueZ version 5
Apr  1 22:41:29 stephan-XPS-13-9360 bluetoothd[950]: Endpoint registered: sender=:1.66 path=/MediaEndpoint/A2DPSource
Apr  1 22:41:30 stephan-XPS-13-9360 bluetoothd[950]: Endpoint registered: sender=:1.66 path=/MediaEndpoint/A2DPSink
Apr  1 22:41:46 stephan-XPS-13-9360 bluetoothd[950]: GATT service objects disabled
Apr  1 22:41:46 stephan-XPS-13-9360 bluetoothd[950]: bt_uhid_send: Invalid argument (22)
Apr  1 22:41:46 stephan-XPS-13-9360 bluetoothd[950]: message repeated 8 times: [ bt_uhid_send: Invalid argument (22)]
Apr  1 22:41:55 stephan-XPS-13-9360 bluetoothd[950]: Endpoint registered: sender=:1.96 path=/MediaEndpoint/A2DPSource
Apr  1 22:41:55 stephan-XPS-13-9360 bluetoothd[950]: Endpoint registered: sender=:1.96 path=/MediaEndpoint/A2DPSink
Apr  1 22:41:55 stephan-XPS-13-9360 bluetoothd[950]: RFCOMM server failed for Headset Voice gateway: rfcomm_bind: Address already in use (98)
Apr  1 22:41:58 stephan-XPS-13-9360 blueproximity[2416]: started.
Apr  1 22:41:58 stephan-XPS-13-9360 dbus-daemon[2062]: Activating via systemd: service name='org.bluez.obex' unit='dbus-org.bluez.obex.service'
Apr  1 22:41:58 stephan-XPS-13-9360 dbus-daemon[2062]: Successfully activated service 'org.bluez.obex'
Apr  1 22:42:13 stephan-XPS-13-9360 bluetoothd[950]: Endpoint unregistered: sender=:1.66 path=/MediaEndpoint/A2DPSource
Apr  1 22:42:13 stephan-XPS-13-9360 bluetoothd[950]: Endpoint unregistered: sender=:1.66 path=/MediaEndpoint/A2DPSink

and

sudo systemctl status dbus-org.bluez.service :

● bluetooth.service - Bluetooth service                                                                                                             
   Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)                                                          
   Active: active (running) since za 2017-04-01 22:41:28 CEST; 1min 45s ago                                                                         
     Docs: man:bluetoothd(8)                                                                                                                        
 Main PID: 950 (bluetoothd)                                                                                                                         
   Status: "Running"                                                                                                                                
    Tasks: 1 (limit: 4915)                                                                                                                          
   CGroup: /system.slice/bluetooth.service                                                                                                          
           └─950 /usr/lib/bluetooth/bluetoothd                                                                                                      

apr 01 22:41:46 stephan-XPS-13-9360 bluetoothd[950]: bt_uhid_send: Invalid argument (22)                                                            
apr 01 22:41:46 stephan-XPS-13-9360 bluetoothd[950]: bt_uhid_send: Invalid argument (22)                                                            
apr 01 22:41:46 stephan-XPS-13-9360 bluetoothd[950]: bt_uhid_send: Invalid argument (22)                                                            
apr 01 22:41:46 stephan-XPS-13-9360 bluetoothd[950]: bt_uhid_send: Invalid argument (22)                                                            
apr 01 22:41:46 stephan-XPS-13-9360 bluetoothd[950]: bt_uhid_send: Invalid argument (22)                                                            
apr 01 22:41:55 stephan-XPS-13-9360 bluetoothd[950]: Endpoint registered: sender=:1.96 path=/MediaEndpoint/A2DPSource                               
apr 01 22:41:55 stephan-XPS-13-9360 bluetoothd[950]: Endpoint registered: sender=:1.96 path=/MediaEndpoint/A2DPSink                                 
apr 01 22:41:55 stephan-XPS-13-9360 bluetoothd[950]: RFCOMM server failed for Headset Voice gateway: rfcomm_bind: Address already in use (98)       
apr 01 22:42:13 stephan-XPS-13-9360 bluetoothd[950]: Endpoint unregistered: sender=:1.66 path=/MediaEndpoint/A2DPSource                             
apr 01 22:42:13 stephan-XPS-13-9360 bluetoothd[950]: Endpoint unregistered: sender=:1.66 path=/MediaEndpoint/A2DPSink                               

How can I find out why power management kills my bluetooth device (and fix this)?

Update: I installed blueman as an alternative manager, but I found out that just installing blueman 'fixes' the problem.

Update 2: Blueman only temporarily fixed the problem. Disabling power management solves the problem now, but that's just a workaround. Still looking for a solution and an explanation why this problem doesn't occur on Unity.

I've got a Dell XPS 13 9360 Developer Edition (Ubuntu 16.10). I'd like to use an ethernet adapter. I've bought a Dell Dock WD15 and a DA200 but I can't get the ethernet connection to work.

When I connect the USB-C cable, these devices show up in the lsusb list:

DA200:

Bus 004 Device 004: ID 0bda:8152 Realtek Semiconductor Corp.

WD 15:

Bus 004 Device 003: ID 0bda:8153 Realtek Semiconductor Corp.

How can I get this ethernet adapter working? Do I need to install extra drivers?

I've tested both devices with a Dell Latitude 7275 and Windows 10 and they're working fine.

Update: results from dmesg | grep -i r815:

[   12.656121] usbcore: registered new interface driver r8152
[   13.438331] r8152 4-1.2:1.0 (unnamed net_device) (uninitialized): Using pass-thru MAC addr d4:81:d7:22:ec:02
[   13.494047] r8152 4-1.2:1.0 eth0: v1.08.6
[   13.666848] r8152 4-1.2:1.0 enxd481d722ec02: renamed from eth0
[  540.891031] r8152 4-1.2:1.0 (unnamed net_device) (uninitialized): Using pass-thru MAC addr d4:81:d7:22:ec:02
[  540.944670] r8152 4-1.2:1.0 eth0: v1.08.6
[  542.486406] r8152 4-1.2:1.0 enxd481d722ec02: renamed from eth0
[ 1223.991503] usbcore: deregistering interface driver r8152
[ 1224.656988] r8152: loading out-of-tree module taints kernel.
[ 1224.657054] r8152: module verification failed: signature and/or required key missing - tainting kernel
[ 1224.824563] r8152 4-1.2:1.0 eth0: v2.08.0 (2016/12/09)
[ 1224.824568] r8152 4-1.2:1.0 eth0: This product is covered by one or more of the following patents:
[ 1224.825680] usbcore: registered new interface driver r8152
[ 1224.826492] r8152 4-1.2:1.0 enx847beb33f1dd: renamed from eth0
[ 1415.312339] r8152 4-1.4:1.0 eth0: v2.08.0 (2016/12/09)
[ 1415.312345] r8152 4-1.4:1.0 eth0: This product is covered by one or more of the following patents:
[ 1427.261311] r8152 4-1.4:1.0 eth0: v2.08.0 (2016/12/09)
[ 1427.261316] r8152 4-1.4:1.0 eth0: This product is covered by one or more of the following patents:
[ 1429.002364] r8152 4-1.4:1.0 enx00249b2352c9: renamed from eth0
[ 1564.756280] r8152 4-1.4:1.0 (unnamed net_device) (uninitialized): Unknown version 0x7cf0
[ 1564.756286] r8152 4-1.4:1.0 (unnamed net_device) (uninitialized): Unknown Device
[ 1629.207955] r8152 4-1.2:1.0 eth0: v2.08.0 (2016/12/09)
[ 1629.207960] r8152 4-1.2:1.0 eth0: This product is covered by one or more of the following patents:
[ 1631.014946] r8152 4-1.2:1.0 enx847beb33f1dd: renamed from eth0
[ 6101.594643] r8152 4-1.4:1.0 eth0: v2.08.0 (2016/12/09)
[ 6101.594649] r8152 4-1.4:1.0 eth0: This product is covered by one or more of the following patents:
[ 6103.232845] r8152 4-1.4:1.0 enx00249b2352c9: renamed from eth0

Output from dmesg | grep enx:

[   13.259620] r8152 4-1.2:1.0 enx847beb33f1dd: renamed from eth0
[  177.044463] r8152 4-1.4:1.0 enx00249b2352c9: renamed from eth0

I really love my task bar, but one annoying thing is the size of this applet (or how do you call it?):

It shows only 5 devices, while I've got many more devices. I've got a very large screen, so I'de like to have this balloon larger. How can I adjust the height of it?

I'm using Kubuntu 16.04 and Plasma 5.6.5.

When I switch between windows or tabs (Chrome, PHPStorm), the rendering of the page doesn't complete. It looks like the screenshot below and only changes when I resize the window or scroll down.

Playing video's is not a problem, so it's not just about slow rendering.

I've got no clue how to debug this problem. How can I find out what's the actual problem?

I'm using a Bluetooth keyboard and all was working fine, until today. It stopped working. My Bluetooth applet says 'No adapters found'. I've got a Asus UX303LA.

When using sudo service bluetooth status, this is the output:

● bluetooth.service - Bluetooth service
   Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
   Active: active (running) since wo 2015-08-12 10:55:09 CEST; 13min ago
 Main PID: 2792 (bluetoothd)
   CGroup: /system.slice/bluetooth.service
           └─2792 /usr/sbin/bluetoothd -n

aug 12 10:55:09 stephan-UX303LA bluetoothd[2792]: bluetoothd[2792]: DIS cannot start: GATT is disabled
aug 12 10:55:09 stephan-UX303LA bluetoothd[2792]: bluetoothd[2792]: Failed to init deviceinfo plugin
aug 12 10:55:09 stephan-UX303LA bluetoothd[2792]: bluetoothd[2792]: Failed to init proximity plugin
aug 12 10:55:09 stephan-UX303LA bluetoothd[2792]: bluetoothd[2792]: Failed to init time plugin
aug 12 10:55:09 stephan-UX303LA bluetoothd[2792]: bluetoothd[2792]: Failed to init alert plugin
aug 12 10:55:09 stephan-UX303LA bluetoothd[2792]: bluetoothd[2792]: Failed to init thermometer plugin
aug 12 10:55:09 stephan-UX303LA bluetoothd[2792]: Failed to init gatt_example plugin
aug 12 10:55:09 stephan-UX303LA bluetoothd[2792]: Bluetooth Management interface initialized
aug 12 10:55:09 stephan-UX303LA bluetoothd[2792]: bluetoothd[2792]: Failed to init gatt_example plugin
aug 12 10:55:09 stephan-UX303LA bluetoothd[2792]: bluetoothd[2792]: Bluetooth Management interface initialized

hcitool dev gives no devices.

How can I figure out what's going wrong?

When I am at slow and/or paid networks (i.e. in public transport wifi of while tethering) I want to browse as fast as possible, so I don't want Ubuntu to download software updates, torrents, etc.

There are many apps that monitor or limit applications, but I can't find an app that works like the 'disable background usage' or 'disable while not on wifi or while roaming' like Android has. I would be great to have an app that disables/limit certain applications when the wifi network is considered as a slow/expensive network.

Recently I've switched from Windows to Ubuntu. I really love it, but one thing is a real pain: my wifi (Dell Vostro V131 notebook, Centrino Wireless-N 1030) isn't working most of the time with different routers. I've spend many hours to fix this problem, but it still doesn't work. The problem is complex, because it's the combination of my wifi card, Ubuntu and some of the networks I try to connect with.

I can connect to a wifi network, but it's very slow (<1 Mbit/s).

To summerize:

• I've reinstalled Ubuntu and switched from Ubuntu 14.04 to Kubuntu 14.10. I've disabled IPv6 and turn off WPA2-security (used a mac-filter instead) and disabled N-mode (Network Issues since Trusty). I've disabled power management and changed many different settings in my router. And I've changed my country code (https://askubuntu.com/a/171398/297583). And I'm sure I forgot 23231 other things I did.
• I've tried many different routers/access points: D-Link DIR-636L, TP-Link TL-WR1043ND, TL-Link TL-WDR3600, ZyXel P-2812HNU-F1 and many others. They all had problems.
• There are many connections that don't have any problems at all. On many other networks, like public hotspots (i.e. in public transport or eduroam at my university) there is no problem.
• When I connect my phone to my notebook with USB (and connect the phone with wifi) it works.
• With an USB dongle (TP-Link TL-WN722N) it works perfectly.
• I haven't got problems in Windows

What else can I try?

If there is no simple solution, maybe it's better to replace the wifi card by another one. In that case, which one do I have to choose? Do I have to replace it by a device that's not on this list (http://wireless.kernel.org/en/users/Drivers/iwlwifi)?

Some configuration/log files:

• /etc/modprobe.d/iwlwifi.conf
• dmesg | grep iwl

Update: high invalid misc value:

When I look at iwconfig I'm seeing a very high 'invalid misc' value:

wlan0     IEEE 802.11bg  ESSID:"Zy_private_XJ7U37"  
    Mode:Managed  Frequency:2.417 GHz  Access Point: CC:5D:4E:1A:3C:7C   
    Bit Rate=54 Mb/s   Tx-Power=15 dBm   
    Retry short limit:7   RTS thr:off   Fragment thr:off
    Power Management:off
    Link Quality=70/70  Signal level=-25 dBm  
    Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
    Tx excessive retries:379  Invalid misc:51889   Missed beacon:0

Another network (no security) is having many errors as well (only one minute connected):

wlan0     IEEE 802.11bg  ESSID:"Test"  
      Mode:Managed  Frequency:2.417 GHz  Access Point: CC:5D:4E:1A:3C:7D   
      Bit Rate=1 Mb/s   Tx-Power=15 dBm   
      Retry short limit:7   RTS thr:off   Fragment thr:off
      Power Management:off
      Link Quality=70/70  Signal level=-25 dBm  
      Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
      Tx excessive retries:48  Invalid misc:1273   Missed beacon:0

Update: switched to WiFi Link 5100

I just removed the wifi card from my previous laptop (Vostro V13). The other card (Intel WiFi Link 5100) doesn't work either.