INSTALLING MINT ON A RELUCTANT TOSHIBA SATELLITE LAPTOP

Downloaded the latest Linux Mint 16 with Mate image via torrent from linuxmint.org. Burned to DVD and used it to boot the Toshiba. All seemed to be going well untill the boot finished and I tried to use the touchpad: no reponse. I tried to use the keyboard to bring up a terminal (<Ctrl><Alt><F2>). Again, no response. Uh-Oh.

Googling for "linux live cd keyboard mouse not working toshiba satellite" brought up some vague forum posts pointing to "function key settings". So, I squinted at the cryptic, grey-on-black icons on the Toshiba's function keys and saw one, <Fn><F9> which might mean "mouse/no mouse".

Pressing this combination brought the mouse and keyboard to life and allowed me to kick-off the installation process.

I  installed the Mint16 root file system (/) on a new 50GB (ext4) partition on my laptop. I used the existing Mint13 swap partition and the existing (ext4) home partition (/home).

I used a new user name ("posh" - short for Petra Toshiba) to avoid overwriting the /home/tosh directory for my existing Mint13 user.

All of this was completly painless using the "expert install" option from the linuxmin.org live cd.

When complete, with all looking well, I rebooted and... ran slap into the same problem: no touchpad or keyboard response. This time however, the <Fn><F9> combo did nothing.

Back to google. A search on "linux toshiba satellite keyboard mouse not working" brought up (amongst a sea of irrelevant crud) some references to i8042. At last, my memory was jogged. Looking at the file /etc/default/grub on my old Mint13 partition I found the line :

# 120623 Added "i8042.nomux=1 i8042.reset nomodeset" to fix

# intermittent touchpad/keyboard bug. Removed "quiet & splash"

Oh well, at least I commented the fix last time.

From Mint13, I edited the Mint16 /boot/grub/grub.cfg file to add these three options to the linux command line: intending to do a proper fix to the Mint 16 /etc/default/grub after a reboot.

Oops. The system seemed to be booting into Mint16 okay, until it tried to bring up X-windows, at which point the system froze with a grey-black screen.

Rebooting into a root shell in recovery mode showed a lot of bitching in the Mint16 /var/log/Xorg.0.log file.

So, time for some trial and error. Rebooted to the grub menu, selected the Mint16 normal boot option and pressed "e" to edit the command line. After a couple of goes, I found that if I removed the "nomodeset" argument, pressed <Ctrl X> to save and reboot, the system booted into Mint16 with working graphics, mouse and touchpad.

Added the line

GRUB_CMDLINE_LINUX_DEFAULT="i8042.nomux=1 i8042.reset"

to the Mint16 file /etc/default/grub and ran

sudo update-grub

to rebuild the Mint16 /boot/grub/grub.cfg.

So what went wrong?

The Toshiba Satellite L775D-S7340 connects the keyboard and touchpad via the motherboard's i8042 PS/2 controller. The Linux driver for the controller assumes support for multiplexing: adding additional PS/2 devices like a trackstick or external PS/2 port. Great on a Thinkpad with a little red nipple thing, not so great on a Toshiba with no extra hardware and hence no multiplexing support. So "i8042.nomux=1 i8042.reset" switches off multiplexing support in the driver and forces a reset of the PS/2 controller.

The "nomodeset" argument in my Mint13 installation was a relict of my having installed prorietary ATI catalyst drivers before addressing the touchpad bug. With the proprietary drivers, the kernel has to stick to default text mode, and leave graphics mode setting to the X-Windows server. With a more recent kernel and the recommended (Mint default) xserver-xorg-video-radeon driver, the nomodeset argument was preventing the kernel from setting the graphics mode (KMS) while X-windows was assuming that graphics mode had already been set by the kernel when trying to startx.

Morals of the story:

1. Don't just comment your tweaks, log them somewhere - like maybe in a hackaday project.

2. Don't just blindly cut-and-paste fixes. Do an extra google-due-dilligence search to understand what you're tweaking.

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Bonus google bomb: before installing Mint16 I'd installed Debian to the same partition. (I quite like Raspbian, so why wait for the Debian->Ubuntu->Mint trickle-down?). The Debian installation went okay (apart from some Stallmanesque hurdles to installing proprietary Wifi, Ethernet and graphics drivers), but the laptop would give me the above grey-black screen on attempting to resume from suspend (opening the lid).

With hindsight, Debian has some version of the same i8042/KMS nomodeset problem when installed on a Toshiba Satellite.