Measurements: Massive Display-related power savings

Michael 'Mickey' Lauer mickey at
Thu Oct 9 03:44:48 CEST 2008

Hi Harald,

Am Mittwoch, den 08.10.2008, 20:43 +0200 schrieb Harald Welte:
> Hi all (Cc'ing mickey since I don't know if you read the kernel list)!

I'm reading it. I'm the userland ambassador :)

> FSO image, screen backlight full on, CPU idle		177mA
> same using frameworkd/sysfs based screen blank		 99mA
> same using manual "sleep" into jbt sysfs file		 83mA
> same using manual "deep-standby" into jbt		 82mA
> same plus disabling glamo DCLK pixel clock		 59mA

Amazing work, well done.

> FSO should switch the backlight control from the sysfs method to the
> fbdev-ioctl method.  It's backwards compatible to old kernels (which will just
> backlight-blank) and future-compatible with kernels that add the jbt6k74
> notifier and glamo fb_blank() patches.

Agreed -- I will reply to your mail to
smartphones-standards at later today.

> This additional battery life time was brougt to you by Swisscom ;)



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