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

From: Sitsofe Wheeler
Date: Mon Sep 15 2008 - 08:57:19 EST


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/
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