Comment 3 for bug 1319035

> * Check BIOS version. Reference http://www.asus.com/Notebooks_Ultrabooks/N55SF/HelpDesk_Download/

BIOS used is version 207, already the latest available from manufacturer. Nothing to do here.

> * Test with latest upstream kernel as per the sentence "Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds ."

Now running
Linux n55sf-l 3.15.0-031500rc5-generic #201405091635 SMP Fri May 9 20:36:31 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
from http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.15-rc5-utopic/linux-image-3.15.0-031500rc5-generic_3.15.0-031500rc5.201405091635_amd64.deb

# Error in logs

Noticed that a message happen regularly in /var/log/kern.log. Here are statistics since november 2012 (date when Ubuntu 13.10 installed). Don't know if related to the problem, though, but it did just happened when plugging smartphone in USB2 port. Unplugging then plugging again it worked.

zgrep "device descriptor read" /var/log/kern.log* -h | grep -o usb.* | sort | uniq -c

     22 usb 1-1.1: device descriptor read/64, error -32
      4 usb 1-1.4: device descriptor read/all, error -71
      1 usb 2-1.3.4: device descriptor read/64, error -110
      8 usb 2-1.3.4: device descriptor read/64, error -32
    398 usb 2-1.3: device descriptor read/64, error -71
     60 usb 2-1.3: device descriptor read/8, error -71
     38 usb 2-1.3: device descriptor read/all, error -71
      4 usb 2-1.4.4: device descriptor read/64, error -32
      4 usb 2-1.4: device descriptor read/64, error -32
    701 usb 2-1.4: device descriptor read/64, error -71
     42 usb 2-1.4: device descriptor read/8, error -71
      1 usb 2-1.4: device descriptor read/all, error -32
     29 usb 2-1.4: device descriptor read/all, error -71
      1 usb 3-1: device descriptor read/64, error -71
      1 usb 3-2: device descriptor read/8, error -110
      2 usb 3-2: device descriptor read/8, error -71

> * Test with Ubuntu 14.04 ?

Does testing latest kernel tagged with "utopic" makes testing Ubuntu 14.04 irrelevant ? Most natural path is that I'll install 14.04 eventually anyway.

# Next step

Latest kernel is not supported by DKMS:

ERROR (dkms apport): kernel package linux-headers-3.15.0-031500rc5-generic is not supported

and I need DKMS for bumblebee support as this laptop had nVidia Optimus technology and if bumblebee is not enabled it draws a lot of power at all times, becomes bery hot, even when machine is idle.

grep . /sys/class/power_supply/BAT0/power_now

27258000

I believe this means that the machine draws 27W when idle.

It feels wrong to use the machine hot like this, I hope it doesn't shorten its life span.

For this reason, I'll be running the regular kernel for daily work and perhaps boot in the latest mainline kernel when bug is salient.

Any hint or instruction appreciated.

Thank you.