Re: Turning off camera also kills card reader on EeePC 900

Sitsofe Wheeler
2008-09-15T12:57:19Z

Alan Jenkins wrote:
> Firstly, I understand these kill-switches are supposed to be persistent
> over reboots. You should check that the SD card stays disabled when you
> reboot.

The settings are persistent (so changing a camera value that is 0 to 1
will show the camera as being enabled if you go to the BIOS). However
the SD card will be present at reboot.

> Next, these settings are also exposed in the BIOS configuration screen,
> right? If it's the same as my 701 then the BIOS will have a separate
> option for disabling the cardreader. So you could see if the platform
> driver "camera" switch is simply disabling and enabling the two switches
> together.

The option for disabling the cardreader is indeed separate from the one
to disable the camera. There is, however a switch for disabling USB in
the BIOS too...

> Or if there's only a BIOS option for the camera, and not the SD card,
> then you should test whether it disables the SD card.

OK there are separate switches in the BIOS for disabling (among other
things) the Camera, CardReader, and USB Ports.

Doing echo 0 > camera when camera is already 0 does nothing. The value
in cardr remains 1.
Doing echo 0 > camera when camera is 1 seemingly results in the SD card
disappearing too (ehci_hcd 0000:00:1d.7: HC died; cleaning up). cardr
value remains 1. The CardReader and USB Ports options will be in the
enabled state when looking in the BIOS after rebooting. The Camera
option will be in the disabled state in the BIOS.
Doing echo 1 > camera after the SD card has disappeared (but before
rebooting) in the above step will result in the SD card seemingly coming
back at a different address and the kernel reporting 'irq 23: nobody
cared (try booting with the "irqpoll" option)' and a usb_hcd_irq backtrace.
Doing echo 0 > cardr when cardr is 1 results in the SD card disappearing
and an ext3 error being printed on the console. The CardReader option
will be in the disabled state in the BIOS after rebooting.
Doing echo 0 > camera after the SD card has disappeared (but before
rebooting) in the above step will result in 'ehci_hcd 0000:00:1d.7: HC
died; cleaning up' being printed.

--
Sitsofe | http://sucs.org/~sits/