# Re: \[PATCH\] Added backlight driver for Acer Aspire 4736

- From: joeyli \<jlee@suse.com\>
- Date: 2012-03-20 03:57:29 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2012/03/3838456
- Thread: https://ratatoskr.run/linux-fbdev/2012/03/3835160/t.md

```text
Hi Pradeep, 

於 一，2012-03-19 於 17:03 +0530，Pradeep Subrahmanion 提到：
> > For the maximum level causes blank screen...
> > 
> > Please kindly help to identify which driver handle the brightness
> > change, run the following 2 commands:
> > 
> > # echo 5 > /sys/class/backlight/acer-wmi/brightness 
> > # echo 5 > /sys/class/backlight/intel_backlight/brightness 
> > 
> > Which one works to change brightness on your machine?
> 
> 	Both  of them do not work for me.Only hot keys are working. 
> 
> Writing to /sys/class/backlight/acer-wmi/brightness 
> 
> and /sys/class/backlight/intel_backlight/brightness do not cause any 
> 
> change in brightness.
> 
> 
> Regards , 
> 
> Pradeep Subrahmanion

A bit strange...

Could you please paste your /proc/cmdline ? Did you add
acpi_osi="Linux" ?


Thanks a lot!
Joey Lee

```