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Wireless LAN device seems to disappear from my laptop PC

I am using my laptop PC (Panasonic CF-N9) with MATE desktop environment based on Debian Jessie, and the network connection is managed by Network Manager software. Recently, the Network Manager started to ignore the wireless LAN device and the wireless LAN connection became unavailable. Here is the snipped kernel log. I guess this is telling me what had happened behind the scene. Once this log was generated, the wireless LAN device seems to disappear during the PCI device detection process of the kernel. Has the wireless LAN device within this PC broken? May 14 22:05:35 gingitsune kernel: [10135.794350] ------------[ cut here ]------------ May 14 22:05:35 gingitsune kernel: [10135.794370] WARNING: CPU: 1 PID: 1833 at /build/linux-AY4Gs5/linux-3.16.43/drivers/net/wireless/iwlwifi/pcie/trans.c:1265 iwl_trans_pcie_grab_nic_access+0xe0/0xf0 [iwlwifi]() May 14 22:05:35 gingitsune kernel: [10135.794372] Timeout waiting for hardware access (CSR_GP_CNTRL 0xffffffff) May 14 22:05:35 ging...

Power saving setting on my laptop machine Debian Jessie is running on

I have not paid a little effort on power-saving setting of my laptop machine, but I finally made it to some extent. After searching around the web pages, the article on the https://forums.bunsenlabs.org/viewtopic.php?id=1920 page reminded me of laptop-mode-tool package and tried it. At first, I installed laptop-mode-tool, rebooted and launched the powertop . The following screen capture is its screen: PowerTOP 2.6.1    Overview   Idle stats   Frequency stats   Device stats   Tunab >> Bad           Wireless Power Saving for interface wlan0                         Bad           Enable Audio codec power management    Bad           Enable SATA link powe...

Using Canon LBP-350 printer with Debian Jessie

I own an old printer, Canon LBP-350. It has both parallel port and USB port, but I never have been able to use it through USB port regardless of several trials. Because my one-year-old main desktop PC with Debian Jessie does not have a parallel port and direct USB connection seems hopeless, I recently bought a USB to Paralell-port convertor. How wonderful, it IS a cable. It has no extra power supply input nor a box at the intermediate location of the cable. I connect the printer and the PC with a little bit peculiar feeling and booted the printer and the PC. Then I opened the system-config-printer panel on the XFCE4 desktop. LBP-350 had already appeared. But the printer was set to inactive state. I couldn't figure out the reason, but I went on. I opened the URL http://lcoalhost:631 and looked into the CUPS administrative page. Yes, the printer was there. I changed the status of the printer to active and pushed the test-page button and the printer printed it. It was not a ...

Trouble shooting: Shift + Alt hijacked on Emacs by some keyboard interceptional function

I have been using MATE desktop environment on my laptop PC since my installation of Debian Jessie. Shortly, I noticed that Emacs M-< and M-> wouldn't work. Since then, I have managed to use the Emacs using ESC key instead of the Alt key as the Meta key. After one year of inconvenient use, I finally find what intercepts the Shift - Alt key. It is keyboard layout switching function of MATE. Here is the screenshot of its setting panel: My next question: Are MATE users happy with this default setting?

Initial normal user's groups of Jessie installation and adduser command default behavior

About two months ago, I installed Debian Jessie (8.1) to the another second-handed laptop PC.  During the install process, I made a non-root normal user account as the installer guided me. One day,  I wanted to add another normal user. Because the Debian system recommendation is to use adduser command, I reviewed its usage and functions. Then I found that the groups to which the initial account belonged were different from the adduser command default groups. I feel peculiar at first, and added the following line to /etc/adduser.conf EXTRA_GROUPS="dialout cdrom floppy audio dip video plugdev netdev lpadmin scanner bluetooth" Then the following command works as expected: adduser --add_extra_groups [new uid] I guess if the tasksel changes the extra-groups default parameters depending on the the purpose of the installation, it is more convenient to the users, at least, to me.

A first step for exim4 configuration

As a system administrator, I have experienced sendmail, qmail and postfix for mail servers. Even after I started to use Debian, I continued to use postfix. But default MTA for Debian is exim4. And now that I am no loger a mail server's administrator,  I feel it's time to try exim4. For several months, I didn't know how to understand exim4 configuration. But finally found hint in /usr/share/doc/exim4/README.Debian.gz   apropos exim Well, I didn't imagine Debian specific configuration guides are in man pages. man exim4-config_files Still, I don't know exim4 configuration syntax, but I can setup a smart host for my laptop PC.

Upgrading wheezy to jessie

I recently upgraded my wheezy box to jessie. As always, upgrade ended in success. It's amazing for me that all the major upgrade have never made my Linux box ruined. I believe that both well-designed package management system and the Debian developer's effort have achieved this result. Thanks a lot, all the contributors!