Troubleshooting wifi connection on an HP Laptop on Ubuntu

So..wifi doesnt connect..most of the time.
Checking:

iwlist scan
enp2s0    Interface doesn't support scanning.

lo        Interface doesn't support scanning.

enxfcde56ff0106  Interface doesn't support scanning.

wlo1      Scan completed :
          Cell 01 - Address: C8:D7:79:50:D4:03
                    Channel:1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=62/70  Signal level=-48 dBm  
                    Encryption key:on
                    ESSID:"hermes"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 18 Mb/s
                    Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=000000150d484187
                    Extra: Last beacon: 7724ms ago
                    IE: Unknown: 00066865726D6573
                    IE: Unknown: 010882848B960C121824
                    IE: Unknown: 030101
                    IE: Unknown: 050400010000
                    IE: Unknown: 2A0104
                    IE: Unknown: 32043048606C
                    IE: Unknown: 2D1A2C101FFFFF000000000000000000000000000000000000000000
                    IE: Unknown: 3D1601000000000000000000000000000000000000000000
                    IE: IEEE 802.11i/WPA2 Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (2) : TKIP CCMP
                        Authentication Suites (1) : PSK
                    IE: Unknown: DD180050F2020101000003A4000027A4000042435E0062322F00
                    IE: Unknown: DD1E00904C332C101FFFFF000000000000000000000000000000000000000000
                    IE: Unknown: DD1A00904C3401000000000000000000000000000000000000000000
                    IE: Unknown: DD0600E04C020160

Creating a config file:

wpa_passphrase myrouter mypassphrase > wpa.conf
[email protected]:~$ cat wpa.conf 
network={
	ssid="myrouter"
	#psk="mypassphrase"
	psk=8ada1f8dbea59704ac379538b4d9191f6a72390581b4cd7a72864cea685b1a7f
}

Now, trying to connect:

wpa_supplicant -Dwext -iwlo1 -c/home/joel/wpa.conf
Successfully initialized wpa_supplicant
ioctl[SIOCSIWENCODEEXT]: Invalid argument
ioctl[SIOCSIWENCODEEXT]: Invalid argument
ioctl[SIOCSIWSCAN]: Device or resource busy
wlo1: CTRL-EVENT-SCAN-FAILED ret=-1 retry=1
ioctl[SIOCGIWSCAN]: Resource temporarily unavailable
ioctl[SIOCSIWSCAN]: Device or resource busy
wlo1: CTRL-EVENT-SCAN-FAILED ret=-1 retry=1
wlo1: Trying to associate with c8:d7:79:50:d4:03 (SSID='hermes' freq=2412 MHz)
ioctl[SIOCSIWFREQ]: Device or resource busy
wlo1: Association request to the driver failed
wlo1: Authentication with c8:d7:79:50:d4:03 timed out.
wlo1: CTRL-EVENT-DISCONNECTED bssid=c8:d7:79:50:d4:03 reason=3 locally_generated=1
ioctl[SIOCSIWSCAN]: Device or resource busy
wlo1: CTRL-EVENT-SCAN-FAILED ret=-1 retry=1
wlo1: Trying to associate with c8:d7:79:50:d4:03 (SSID='hermes' freq=2412 MHz)
ioctl[SIOCSIWFREQ]: Device or resource busy
wlo1: Association request to the driver failed
wlo1: Authentication with c8:d7:79:50:d4:03 timed out.
wlo1: CTRL-EVENT-DISCONNECTED bssid=c8:d7:79:50:d4:03 reason=3 locally_generated=1
wlo1: CTRL-EVENT-SSID-TEMP-DISABLED id=0 ssid="hermes" auth_failures=1 duration=10 reason=CONN_FAILED
ioctl[SIOCSIWSCAN]: Device or resource busy
wlo1: CTRL-EVENT-SCAN-FAILED ret=-1 retry=1
wlo1: CTRL-EVENT-SSID-REENABLED id=0 ssid="hermes"
wlo1: Trying to associate with c8:d7:79:50:d4:03 (SSID='hermes' freq=2412 MHz)
ioctl[SIOCSIWFREQ]: Device or resource busy
wlo1: Association request to the driver failed
wlo1: Authentication with c8:d7:79:50:d4:03 timed out.
wlo1: CTRL-EVENT-DISCONNECTED bssid=c8:d7:79:50:d4:03 reason=3 locally_generated=1
wlo1: CTRL-EVENT-SSID-TEMP-DISABLED id=0 ssid="hermes" auth_failures=2 duration=23 reason=CONN_FAILED
ioctl[SIOCSIWSCAN]: Device or resource busy
wlo1: CTRL-EVENT-SCAN-FAILED ret=-1 retry=1
wlo1: CTRL-EVENT-SSID-REENABLED id=0 ssid="hermes"
wlo1: Trying to associate with c8:d7:79:50:d4:03 (SSID='hermes' freq=2412 MHz)
ioctl[SIOCSIWFREQ]: Device or resource busy
wlo1: Association request to the driver failed
wlo1: Authentication with c8:d7:79:50:d4:03 timed out.
wlo1: CTRL-EVENT-DISCONNECTED bssid=c8:d7:79:50:d4:03 reason=3 locally_generated=1
wlo1: CTRL-EVENT-SSID-TEMP-DISABLED id=0 ssid="hermes" auth_failures=3 duration=46 reason=CONN_FAILED
ioctl[SIOCSIWSCAN]: Device or resource busy
wlo1: CTRL-EVENT-SCAN-FAILED ret=-1 retry=1
ioctl[SIOCSIWSCAN]: Device or resource busy
wlo1: CTRL-EVENT-SCAN-FAILED ret=-1 retry=1
wlo1: CTRL-EVENT-SSID-REENABLED id=0 ssid="hermes"
wlo1: Trying to associate with c8:d7:79:50:d4:03 (SSID='hermes' freq=2412 MHz)
ioctl[SIOCSIWFREQ]: Device or resource busy
wlo1: Association request to the driver failed
wlo1: Authentication with c8:d7:79:50:d4:03 timed out.
wlo1: CTRL-EVENT-DISCONNECTED bssid=c8:d7:79:50:d4:03 reason=3 locally_generated=1
wlo1: CTRL-EVENT-SSID-TEMP-DISABLED id=0 ssid="hermes" auth_failures=4 duration=77 reason=CONN_FAILED
^Cwlo1: CTRL-EVENT-TERMINATING 

More (http://askubuntu.com/questions/461825/connect-to-wifi-from-command-line/461831#461831):

nmcli c
NAME                  UUID                                  TYPE             DEVICE          
Wired connection 2    f79d239b-6e57-348d-bbd9-f689917d86b4  802-3-ethernet   enxfcde56ff0106 
Angels pride          c1f5f213-4a9f-4f27-a8d4-24d0e584f45d  802-11-wireless  --              
Lourde WIFI_Internet  b090d381-42c6-40b1-af61-13410d764b89  802-11-wireless  --              
Wired connection 1    1564ea51-0724-3c47-942d-3c376a1c0cd5  802-3-ethernet   --              
hermes                4a596b2d-b365-46dd-bfb2-62dd912a919e  802-11-wireless  --              
wirezone              ecbdb1ef-b8bb-46ed-bb57-e11d02d3ec2f  802-11-wireless  --            

Showing wifi interface:

# nmcli d wifi list
*  SSID    MODE   CHAN  RATE       SIGNAL  BARS  SECURITY 
   hermes  Infra  1     54 Mbit/s  90      ▂▄▆█  WPA2  

Now checking the kernel driver (http://askubuntu.com/questions/635625/how-do-i-get-a-realtek-rtl8723be-wireless-card-to-work):

# lspci -knn | grep Net -A2
03:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter [10ec:b723]
	DeviceName: Sanji2 
	Subsystem: Hewlett-Packard Company RTL8723BE PCIe Wireless Network Adapter [103c:81c1]
	Kernel driver in use: rtl8723be
	Kernel modules: rtl8723be
ifconfig && iwconfig && route -n && ping -c 1 google.com
enp2s0    Link encap:Ethernet  HWaddr ec:8e:b5:fc:f1:6e  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

enxfcde56ff0106 Link encap:Ethernet  HWaddr fc:de:56:ff:01:06  
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:27144 errors:2 dropped:0 overruns:0 frame:2
          TX packets:21691 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:28661096 (28.6 MB)  TX bytes:4098261 (4.0 MB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:6799 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6799 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1 
          RX bytes:513684 (513.6 KB)  TX bytes:513684 (513.6 KB)

wlo1      Link encap:Ethernet  HWaddr 54:8c:a0:79:10:77  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:141 errors:0 dropped:0 overruns:0 frame:0
          TX packets:419 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:17910 (17.9 KB)  TX bytes:51220 (51.2 KB)

enp2s0    no wireless extensions.

lo        no wireless extensions.

enxfcde56ff0106  no wireless extensions.

wlo1      IEEE 802.11bgn  ESSID:off/any  
          Mode:Managed  Frequency:2.412 GHz  Access Point: Not-Associated   
          Tx-Power=20 dBm   
          Retry short limit:7   RTS thr=2347 B   Fragment thr:off
          Encryption key:off
          Power Management:off

Installing a good driver:

sudo add-apt-repository ppa:hanipouspilot/rtlwifi
sudo apt-get update
sudo apt-get install rtlwifi-new-dkms

Rebooting..


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.
Uber customer support personnel are vindictive and illmannered

Uber customer support personnel are vindictive and illmannered

When Uber was launched in Trivandrum half a year ago, I was one of the first to embrace this low cost solution for transportation which seemed at the time to be a boon to the common man, to escape the clutches of fleecing autorickshaw and taxi drivers. Recently however I was taken aback by the response from Uber customer support to a situation where I was at the receiving end when a taxi driver cancelled on me, at 3 a.m. after having booked a taxi 10 minutes ago.

It is at 3 a.m that the Palakkad Town bound Amritha Express reaches Ernakulam North railway station. Amritha express is two trains joined as one, including both Amritha Express and the Rajya Rani express. Hence, the train is very long, and the Rajya Rani coaches almost stretch out of the station when the rear end of Amritha express parks at the station entrance. If you were unlucky enough to be on Rajya rani coaches, you need to walk half a kilometre to the station’s prepaid autorickshaw counter. By that time, there would be a very long queue, and often, you may need to wait for the autorickshaws on trips to return. Anticipating this, on 20th April, 2:50pm, I booked an Uber cab while the train was pulling into Ernakulam North railway station. For the booking, I used the app to search for Ernakulam North railway station as the starting location. A driver named Vineeth accepted the trip, and confirmed that he would arrive in 10 minutes, and requested that I wait for him. Having waited for 15 minutes, I checked the app and found that the driver had cancelled the trip on his own, without even informing me. By that time, there was as expected an extremely long queue at the autorickshaw counter, and no autorickshaws available. When I rechecked Uber, I found that it was now showing surge pricing. I decided therefore to wait for an auto.

Having reached my destination, I shot off a complaint to Uber regarding the driver who never turned up. Imagine my extreme chagrin when I received a reply from Uber customer support, alleging misuse of the system by me, and threatening to terminate my Uber account if such malpractise was noticed in future. The mail I received follows:

“Hi Joel,

I’m reaching out because we received feedback from one of your recent trips that the request location and pick up location were very far apart from each other. Upon further investigation, it looks as though the request location was within a surged pricing zone and the dropped pin was not.

Dynamic pricing allows us to quickly get more drivers on the road to serve you during busy times. Our intent is to make sure we’re the most reliable ride out there so you aren’t left stranded. You always have the choice of whether to request a ride or not, and we provide full transparency about dynamic pricing in your app before, during, and after you request a ride. Manipulating this system is misuse of the application and is frustrating for our driver-partners. Should we hear of future similar complaints, we may have to suspend your use of the app.

We appreciate you riding with us so far and would like to see you continue to use Uber.

Safety and accountability is built into the Uber experience, before, during and after a ride. Read more.

Regards,

SHERANCE JOSEPH
help.uber.com”

In fact, his insinuations were false. While booking my ride, I had booked my searching the location via the Uber app, and then booking the ride. Apparently that location, and the actual GPS based PIN (PIN in Uber, is the GPS coordinate of the pickup location) of the railway station was different. The glitch could have crept in because searching by location name utilizes Google Maps’ preset GPS coordinates for a location, and searching via auto-discovered GPS location searches exact location. These could match two entirely different loations seperated by some distance. Because I’m technically inclined and bothered to look into it, I discovered this.

Imagine the effect of wanton allegations levelled against a prospective customer? Do you actually want customers to give your service a miss? I most vehemently place on record my anger at Mr Sherance’s allegations without looking whether there was a technical fault at your end. In fact last week, I found that Uber had overcharged me for a ride I took, and on investigation Uber confirmed that there was a technical glitch causing it. I am well within my rights to file a consumer case for that instance. Software systems are not perfect. Rectify your fault before alleging blame on someone else!
Like and Share this post to spread awareness.

Screenshot_20160421-172638


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Windows 10 Blue Screen – VIDEO_TDR_FAILURE igdkmd64.sys

Update your video driver if you can boot into Windows occasionally. Else you probably will have to remove the file from Linux/Safe Mode and reboot.


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Installing Kubuntu 12.04 on Acer Aspire V5-121 Netbook

I recently bought an Acer Aspire V5-121.

Installation went smoothly. But on rebooting I found the following issues:

  • Wifi did not work
  • USB 3.0 did not work
  • Touchpad did not work

Fix for Wifi:

In KDE Menu, type `driver`, to bring up the Additional Drivers link for installing Proprietary drivers. Choose to install the Broadcom STA wireless driver. On installing this driver and rebooting, USB 3.0 too started working.

For enabling Touchpad, all I needed was to press Ctrl-Fn-F7


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Install HP Laserjet P1007 in Debian and Ubuntu

This was the easiest installation I’ve ever seen in a Linux distro, comparable to Windows Plug and Play

I plugged in my printer. As expected nothing happened. I tried to fathom what happened:

[[email protected] c]$ sudo tail -f /var/log/messages
Dec  7 10:49:38 debian kernel: [ 6316.051712] usb 1-7.1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Dec  7 10:49:38 debian kernel: [ 6316.051715] usb 1-7.1.2: Product: HP LaserJet P1007
Dec  7 10:49:38 debian kernel: [ 6316.051718] usb 1-7.1.2: Manufacturer: Hewlett-Packard
Dec  7 10:49:38 debian kernel: [ 6316.051720] usb 1-7.1.2: SerialNumber: EC0FCLS
Dec  7 10:49:38 debian kernel: [ 6316.051849] usb 1-7.1.2: configuration #1 chosen from 1 choice
Dec  7 10:49:39 debian kernel: [ 6316.635466] usblp1: USB Bidirectional printer dev 7 if 0 alt 0 proto 2 vid 0x03F0 pid 0x4817
Dec  7 10:49:39 debian kernel: [ 6316.635500] usbcore: registered new interface driver usblp
Dec  7 10:49:39 debian kernel: [ 6317.567202] usb 1-7.1.2: usbfs: interface 0 claimed by usblp while 'usb' sets config #1
Dec  7 10:49:42 debian /usr/sbin/hpljP1007: foo2zjs: Missing HP LaserJet P1007 firmware file /lib/firmware/hp/sihpP1005.dl
Dec  7 10:49:42 debian /usr/sbin/hpljP1007: foo2zjs: ...read foo2zjs installation instructions and run ./getweb P1007

That was very instructive. Ok, so I have to execute ./getweb. From where.

Since it said foo2zjs I tried to find out where foo2zjs was located

[[email protected] c]$ which foo2zjs
/usr/bin/foo2zjs

Great. So:

[[email protected] c]$ cd /usr/bin
[[email protected] bin]$ which foo2zjs
/usr/bin/foo2zjs
[[email protected] bin]$ ./getweb P1007
You need to be root
[[email protected] bin]$ sudo ./getweb P1007
sihpP1005.img

(c) Copyright Hewlett-Packard 2008

[[email protected] bin]$ sudo tail -f /var/log/messages
Dec  7 10:49:38 debian kernel: [ 6316.051712] usb 1-7.1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Dec  7 10:49:38 debian kernel: [ 6316.051715] usb 1-7.1.2: Product: HP LaserJet P1007
Dec  7 10:49:38 debian kernel: [ 6316.051718] usb 1-7.1.2: Manufacturer: Hewlett-Packard
Dec  7 10:49:38 debian kernel: [ 6316.051720] usb 1-7.1.2: SerialNumber: EC0FCLS
Dec  7 10:49:38 debian kernel: [ 6316.051849] usb 1-7.1.2: configuration #1 chosen from 1 choice
Dec  7 10:49:39 debian kernel: [ 6316.635466] usblp1: USB Bidirectional printer dev 7 if 0 alt 0 proto 2 vid 0x03F0 pid 0x4817
Dec  7 10:49:39 debian kernel: [ 6316.635500] usbcore: registered new interface driver usblp
Dec  7 10:49:39 debian kernel: [ 6317.567202] usb 1-7.1.2: usbfs: interface 0 claimed by usblp while 'usb' sets config #1
Dec  7 10:49:42 debian /usr/sbin/hpljP1007: foo2zjs: Missing HP LaserJet P1007 firmware file /lib/firmware/hp/sihpP1005.dl
Dec  7 10:49:42 debian /usr/sbin/hpljP1007: foo2zjs: ...read foo2zjs installation instructions and run ./getweb P1007

So it downloaded the file but again gave the same message. I decided to unplug and replug the printer.

Sure enough I was greeted by the familiar startup sound of the printer… And confirmation from syslog:

[[email protected] bin]$ sudo tail -f /var/log/messages
Dec  7 10:53:42 debian kernel: [ 6560.287745] usb 1-7.1.2: New USB device found, idVendor=03f0, idProduct=4817
Dec  7 10:53:42 debian kernel: [ 6560.287750] usb 1-7.1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Dec  7 10:53:42 debian kernel: [ 6560.287754] usb 1-7.1.2: Product: HP LaserJet P1007
Dec  7 10:53:42 debian kernel: [ 6560.287756] usb 1-7.1.2: Manufacturer: Hewlett-Packard
Dec  7 10:53:42 debian kernel: [ 6560.287759] usb 1-7.1.2: SerialNumber: EC0FCLS
Dec  7 10:53:42 debian kernel: [ 6560.287903] usb 1-7.1.2: configuration #1 chosen from 1 choice
Dec  7 10:53:42 debian kernel: [ 6560.290938] usblp1: USB Bidirectional printer dev 8 if 0 alt 0 proto 2 vid 0x03F0 pid 0x4817
Dec  7 10:53:43 debian kernel: [ 6561.402520] usb 1-7.1.2: usbfs: interface 0 claimed by usblp while 'usb' sets config #1
Dec  7 10:53:45 debian /usr/sbin/hpljP1007: foo2zjs: loading HP LaserJet P1007 firmware /lib/firmware/hp/sihpP1005.dl to /dev/usb/lp1 ...
Dec  7 10:53:46 debian /usr/sbin/hpljP1007: foo2zjs: ... download successful.
Dec  7 10:53:58 debian udev-configure-printer: Re-enabled printer ipp://localhost:631/printers/HP-LaserJet-P1007

Going to the printers applet, I could see a new Laserjet P1007 installed. Installed a test print.

Related info can be found here.

Install printer in Kubuntu 12.10

It was too easy. Everything was Plug and play.

However if it doesnt install for you, you can try downloading the file from HP and installing it:

First use the system script to download the driver:

/usr/bin/python /usr/bin/hp-plugin -i

Now install it:

sh /tmp/hplip-3.12.6-plugin.run --nox11 -- -i
[[email protected] droidzone]#/usr/bin/python /usr/bin/hp-plugin -i

HP Linux Imaging and Printing System (ver. 3.12.6)
Plugin Download and Install Utility ver. 2.1

Copyright (c) 2001-14 Hewlett-Packard Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

error: PolicyKit support requires DBUS or PolicyKit support files missing
(Note: Defaults for each question are maked with a '*'. Press <enter> to accept the default.)

\
-----------------------------------------
| PLUG-IN INSTALLATION FOR HPLIP 3.12.6 |
-----------------------------------------

The driver plugin for HPLIP 3.12.6 appears to already be installed.
Do you wish to download and re-install the plug-in? (y=yes*, n=no, q=quit) ?

 

sh /tmp/hplip-3.12.6-plugin.run --nox11 -- -i
Verifying archive integrity... All good.
Uncompressing HPLIP 3.12.6 Plugin Self Extracting Archive.......................................................

HP Linux Imaging and Printing System (ver. 3.12.6)
Plugin Installer ver. 3.0

Copyright (c) 2001-14 Hewlett-Packard Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

Plug-in version: 3.12.6
Installed HPLIP version: 3.12.6
Number of files to install: 50

You must agree to the license terms before installing the plug-in:

LICENSE TERMS FOR HP Linux Imaging and Printing (HPLIP) Driver Plug-in   
........................
Do you accept the license terms for the plug-in (y=yes*, n=no, q=quit) ? y

Done.

 

 

d


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Kernel source locations

Capacitative touch keys:

Machine specific driver for GPS module : /home/droidzone/android/kernel/arch/arm/mach-exynos/bcm4752.c:


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Nvidia driver issue on Kubuntu 12.05

I’d upgraded Kubuntu 11.10 to 12.05, then accidentally run the Nvidia installer, overwriting my kernel module with an older module. At boot, I got the following error message:

NVRM: API mismatch-client has version 295.20 while module has version 295.40
No screens found, X cannot start. Some configurations were found but were unusable.

I could not reinstaller the NVidia installer again.

Solution:
Found out the kernel module location:

[[email protected] ~]$ modprobe -l |grep nvidiakernel/drivers/video/nvidia/nvidiafb.ko
kernel/drivers/net/ethernet/nvidia/forcedeth.ko
kernel/drivers/video/nvidia.ko
[[email protected] ~]$ ls -l /lib/modules/
total 12
drwxr-xr-x 3 root root 4096 May 8 06:47 3.0.0-12-generic
drwxr-xr-x 5 root root 4096 May 8 23:05 3.0.0-19-generic
drwxr-xr-x 5 root root 4096 May 8 23:06 3.2.0-24-generic
[[email protected] ~]$ sudo mv /lib/modules/3.2.0-24-generic/kernel/drivers/video/nvidia nvidia_old/
[[email protected] ~]$ sudo mv /lib/modules/3.2.0-24-generic/kernel/drivers/vi nvidia_old/video/ virtio/
[[email protected] ~]$ sudo mv /lib/modules/3.2.0-24-generic/kernel/drivers/video/nvidia.ko nvidia_old/
[/code]
Load muon software installer and uninstall the Nvidia package.

Running the command:

dkpg-reconfigure xserver-xorg[/code]
will fix your
xorg.conf if you mess it up, but it won't fix the API mismatch (via http://ubuntuforums.org/showthread.php?t=650161)

Update: The above did not work for me this time. After purging the module, and downloading and reinstalling the Nvidia official installation, the system gave me the ubiquitous green and black screen.

What I did to solve my issue:
Boot into recovery root shell.

dpkg --purge nvidia-*[/code]
It will give a warning that nvidia-common cannot be uninstalled due to dependency issues, but that's fine.

Boot into recovery, then into graphical screen.
Open muon software installer and install the current driver.
If you're using apt, it will be:

apt-get install nvidia-current[/code]

reboot and you're good to go!

 

Update on the issue:

The issue recurred a few weeks later. I dont remember modifying anything in Ubuntu at the time, but somehow I got the same message that the kernel module conflicted with an API. I tried:

dpkg --purge nvidia*

But it said nvidia-common could not be removed as it was a dependency for KDE. I forced a purge with:

dpkg --purge --force-all nvidia*

Rebooting would not have started nvidia, so I rebooted to recovery and resumed.


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Installing HP Laserjet P1007 printer on Ubuntu 11.10

Credits: Tejasbarot.com, foo2xqx project

This is the quick and easy method to install the printer on Ubuntu. Tested on Ubuntu 11.10 under KDE.

    1. Download foo2xqx.
      wget -O foo2zjs.tar.gz http://foo2zjs.rkkda.com/foo2zjs.tar.gz[/code]OR

      wget -O foo2zjs.tar.gz http://droidzone.in/misc/ubuntu/drivers/hplaserjet/p1007/foo2zjs.tar.gz[/code]
    2. Extract the downloaded package
      tar zvxf foo2zjs.tar.gz[/code]
    3. Execute the following code to compile the driver, install it and to configure a new printer
      cd foo2zjs/
      make
      ./getweb P1007
      sudo make install
      sudo apt-get install system-config-printer-gnome
      system-config-printer[/code]
      At this point, you get a popup box with a Printer driver. Double click on HP Laserjet P1007 to install a new driver.
    4. Configure Plug and Play:
      sudo make install-hotplug[/code]
      At this point, you may be prompted to uninstall system-config-printer-udev.

      [[email protected] foo2zjs]$ sudo make install-hotplug
      #
      # Hotplug Installation Dependencies...
      #
      ***
      *** Error: system-config-printer-udev is installed!
      ***
      *** Remove it with: (Fedora)
      *** # yum remove system-config-printer-udev
      *** OR
      *** # rpm -e --nodeps system-config-printer-udev
      *** OR (Ubuntu, Debian)
      *** $ sudo apt-get remove system-config-printer-udev
      *** OR (generic linux)
      *** # rm -f /lib/udev/rules.d/*-printers.rules
      ***
      make: *** [install-hotplug-test] Error 1
      [/code]
      Do it.

      [[email protected] foo2zjs]$ sudo apt-get remove system-config-printer-udev
      Reading package lists... Done
      Building dependency tree
      Reading state information... Done
      The following packages will be REMOVED:
      system-config-printer-udev
      0 upgraded, 0 newly installed, 1 to remove and 378 not upgraded.
      After this operation, 131 kB disk space will be freed.
      Do you want to continue [Y/n]? y
      (Reading database ... 141596 files and directories currently installed.)
      Removing system-config-printer-udev ...
      [[email protected] foo2zjs]$ sudo make install-hotplug
      [/code]
      At this point, you can see your printer initialize with its peculiar sound.

Now you're all set to print any document.

 

 


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Installing Nvidia Graphics driver under Kubuntu

I’ve had a weird issue. My Kubuntu install would never start Xorg. I could boot to recovery, then make it “resume normal boot”. But it would never boot on its own. I pinned the issue on graphics drivers.

 

 

My Graphics Processor is Nvidia GeForce 8400 GS

 

 

Driver download page

Latest Ubuntu 32 bit display driver (as of Jan 23, 2012)

 

 

This downloads a 32 MB executable file NVIDIA-Linux-x86-290.10.run

Boot to Ubuntu recovery, navigate to the folder containing NVIDIA-Linux-x86-290.10.run

 

 

First install binaries required to rebuild kernel:

 

 

sudo apt-get install build-essential[/code]

 

 

Then install the driver:

sh NVIDIA-Linux-x86-290.10.run[/code]

 

Now you can start X with:

sudo /etc/init.d/kdm start[/code]

 

Add Nvidia module to start with

kdesudo kate /etc/modules[/code]

Add a line "nvidia" on a new line
Once Nvidia drivers are installed, you can configure them with:

kdesudo nvidia-settings[/code]

For more instructions, refer the following:

https://help.ubuntu.com/community/NvidiaManual


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Kernel compilation error – Undefined reference to `swap_info’

mm/built-in.o: In function `frontswap_curr_pages':
/home/droidzone/android/kernel/banana/bravo_2.6.35_gb-mr/mm/frontswap.c:235: undefined reference to `swap_list'
/home/droidzone/android/kernel/banana/bravo_2.6.35_gb-mr/mm/frontswap.c:235: undefined reference to `swap_info'
mm/built-in.o: In function `frontswap_shrink':
/home/droidzone/android/kernel/banana/bravo_2.6.35_gb-mr/mm/frontswap.c:207: undefined reference to `try_to_unuse'
/home/droidzone/android/kernel/banana/bravo_2.6.35_gb-mr/mm/frontswap.c:214: undefined reference to `swap_list'
/home/droidzone/android/kernel/banana/bravo_2.6.35_gb-mr/mm/frontswap.c:214: undefined reference to `swap_info'
mm/built-in.o: In function `__frontswap_put_page':
/home/droidzone/android/kernel/banana/bravo_2.6.35_gb-mr/mm/frontswap.c:104: undefined reference to `swap_info'
mm/built-in.o: In function `__frontswap_get_page':
/home/droidzone/android/kernel/banana/bravo_2.6.35_gb-mr/mm/frontswap.c:125: undefined reference to `swap_info'
mm/built-in.o: In function `__frontswap_flush_page':
/home/droidzone/android/kernel/banana/bravo_2.6.35_gb-mr/mm/frontswap.c:139: undefined reference to `swap_info'
mm/built-in.o: In function `__frontswap_flush_area':
/home/droidzone/android/kernel/banana/bravo_2.6.35_gb-mr/mm/frontswap.c:153: undefined reference to `swap_info'
make: *** [.tmp_vmlinux1] Error 1
ERROR: An error occured. Kernel was not compiled.[/code]

Disable the following options in menuconfig:
Kernel Features>Enable frontswap driver, Enable Cachecleaner driver


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.