This guide cover ONLY Inspiron 15R series specific the 15R 5XXX series. Must not to be confused with the first Inspiron 15 series that are similar but not same.

Machine Overall

Good performance for some multimedia task. Due the arrow keys are too small, very uncomfortable for office typing or programming, special keys are too away.. the screen are too small from top to bottom in space…

Devuan performance

Due its 4 cores can be installed KDE inclusivelly, without performance problems, but for large video files or Databases task there's a impact due discs limitations.

Devuan and any recent Linux at 2017 January, as standard installation coverts without problems all standard hardware, with most of the features enabled.

Overall Devuan status

Core Components status Observations
Boot standar kernel Yes
CPU Frequency Scaling Yes
Hibernation Yes needs extra package
Sleep/Suspend Yes needs extra package
Optical CD/DVD/BD Yes
Detect hard drives Yes
Supports SDD drives Yes needs extra work
USB Yes support 2.0 and 3.0
Overall temperature below 72
UEFI/EFI Supported needed if BIOS enabled
Network devices status Observations
LAN network card: Supported Need firmware
Wifi network card Supported Need firmware
Xorg and video status Observations
Primary video card Yes Intel discrete
Discrete video card Yes radeon needs firmware
Resize-and-Rotate ? not tested
HDMI out Yes seems only with radeon discrete
VGA out N/A
Sound support status Observations
ALSA Yes May need work respect HDMI
OSS4 Yes
OSS No support emulation alsa
Input devices status Observations
Keyboard Yes
Mouse/Touchpad Yes
Touchscreen Yes
Webcam Yes
Keyboard's Hotkeys Supported needs work, mayor desktop works
Card reader SD/MMC Yes
Power devices status Observations
ACPI S3/S4/FAN Yes good
Battery Supported some issues getting info

Overall install status:

The installer isos will install wireless firmware unless you select expert install and say you don't want it. In the live isos, wireless firmware and firmware-linux-nonfree are installed and can be removed after installation by running a script.

At install process if choice standard from start (no live), the touch screen acts as mouse device so mouse normal movement will not work, but buttons and touche of both devices works well.

No mayor fine tune need: Mayor desktop flavors such as MATE, Gnome, KDE, XFce or Cinnamon will autoconfigure the most, and special keys and/or function keys. Only if you will use different desktop, audio and discrete card needs works and fine tune, the networking only need firmware and automatically begin to work.

Network

Unfortunately all the networking devices need firmware. At installation steps with official images, the computer remains uncommunicative after completing install, so its recommended download specific packages for each module or put inside their USB device if you install by the USB way:

Network device kernel module firmware package Observations
LAN r8169 firmware-realtek
Wifi iwlwifi firmware-iwlwifi

Based on intel info, seems support monitor and promiscuous modes https://communities.intel.com/thread/63510 ; but some devices are not responding, https://ubuntuforums.org/showthread.php?t=2214854 so cracking of Wifi networks may not be possible due the modinfo reports no support.

Audio

All the laptops with HDMI sound load the HDMI card as default; HDMI is the default sound card for moderns, which is the reason it shows only digital output, if no digital sound its present, no sound will be heard.

Audio device kernel module firmware package Observations
Intel HAskel ULT snd_hda_intel loaded as default
Intel HD audio snd_hda_intel real sound card

Identify the audio devices

Due ALSA, default card are the HDMI with digital audio, using lspci can be identifyed the audio cards:

lspci -vnn | grep -A 9 -i audio | awk '/udio/ || /driver/ { print; }'
00:03.0 Audio device [0403]: Intel Corporation Haswell-ULT HD Audio Controller [8086:0a0c] (rev 09)
Kernel driver in use: snd_hda_intel
00:1b.0 Audio device [0403]: Intel Corporation 8 Series HD Audio Controller [8086:9c20] (rev 04)
Kernel driver in use: snd_hda_intel

Set the audio devices

For Mayor desktops, the stupid “pulse” framework system audio property select the main device as general out, but due pulseaudio are too heavy and not standard.. many (around 80%) of specific applications (some games, emulators, independent multimedia managers) doesn't work

For minor and light desktop you must set in modprobe.d a alsa.conf file preceded by a number, with the proper options to set default analog audio card as primary loaded, the content of the file will be as:

options snd_hda_intel enable=1 index=0
options snd_hda_intel index=1

Video

All the R15 models comes with two GPU, one Intel as IGD or integrated and other Ati as DIS or discrete, for more info about please read if u dont know: https://wiki.archlinux.org/index.php/hybrid_graphics

Video device (Xorg) kernel module firmware package Observations
Intel HAskel ULT/Ivy Bridge i915
AMD Radeon HD 86XX/HD 7XXXM radeon firmware-linux-nonfree output only by the HDMI
Video device (AMD) kernel module firmware package Observations
Ati Radeon HD 86XX/HD 7XXXM fglrx fglrx-driver fglrx-modules-dkms not tested,not recomended

Take in consideration that the “discrete” are not discrete at all, a right OS make a hierarchy process level for applications, due that technology are develop for stupid guindo-like the Linux subsystem switch are very hard, due the rendering infrastructure was prepared and runnig before any app, and the “discrete” (really?) spect that app can “grab” a rendering task braking the userspace of the graphics..

Identify the video devices

Due modern laptop, comes with discrete a two GPU sets:

lspci -v|grep -A 11 -i ispla |awk '/ispla/ || /driver/ { print; }';lspci -v|grep -A 11 -i VGA | awk '/VGA/ || /driver/ { print; }'
03:00.0 Display controller [0380]: Advanced Micro Devices, Inc. [AMD/ATI] Sun XT [Radeon HD 8XXXM] [1002:6660]
Kernel driver in use: radeon
00:02.0 VGA compatible controller [0300]: Intel Corporation Haswell-ULT Integrated Graphics Controller [8086:0a16]
Kernel driver in use: i915

Default Devuan settings

Devuan installs XOrg modules, using intel as default primary and raedon casually for HDMI out, performance fortunately are good and those issues about heat and high consumption are gone. No pci_aspm are need and no overhead are noted using only the intel card, inclusively the intel card are more stable and good performance rather than the radeon card.

Manage by open source way: using Xorg and modeset

Any DELL 15R laptop its a more modern generation of this “hybrid” technology, so the switching are now managed using software.. u need at least Devuan 1.0.0 or jessie with recent xrandr installed.

The debugfs are need for all vgaswitcherro operations, can be mounted by “mount” command, and also added to fstab registering the entry in fstab CAUTION the echo must be done one time only:

mount -t debugfs none /sys/kernel/debug
echo "debugfs               /sys/kernel/debug   debugfs   defaults   0   0" >> /etc/fstab

Identify using vgaswitcherro way, need the debugfs mounted for kernel and the search for the “Pwr” string, remenber verify if debugfs are mounted first:

cat /sys/kernel/debug/vgaswitcheroo/switch
0:IGD:+:Pwr:0000:00:02.0
1:DIS: :DynOff:0000:03:00.0

Disabling the ATI discrete and use only Intel: due the ADM/Ati card are a display type, only one was powered on, but its not the case, can be managed and turn off, but CAUTION, this can turn off both cards, please test at your own risk:

echo OFF >/sys/kernel/debug/vgaswitcheroo/switch
echo MIGD >/sys/kernel/debug/vgaswitcheroo/switch
echo IGD >/sys/kernel/debug/vgaswitcheroo/switch
echo OFF >/sys/kernel/debug/vgaswitcheroo/switch

Disabling the Intel integrated and use only AMD Ati: before doint its recomended to restart all the xorg, so firts stop display manager (default in Devuan are slim) and then switch the GPU, but CAUTION, this can turn off both cards, please test at your own risk:

echo OFF >/sys/kernel/debug/vgaswitcheroo/switch
echo MDIS >/sys/kernel/debug/vgaswitcheroo/switch
echo DIS >/sys/kernel/debug/vgaswitcheroo/switch
echo OFF >/sys/kernel/debug/vgaswitcheroo/switch

Control the app and rendered method: can be made using the xrandr utility, a program can render using the other card, but until this article, the output its only to the HDMI out:

xrandr --listproviders
Providers: number : 2
Provider 0: id: 0x76 cap: 0xb, Source Output, Sink Output, Sink Offload crtcs: 3 outputs: 4 associated providers: 0 name:Intel
Provider 1: id: 0x4f cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 0 outputs: 0 associated providers: 0 name:radeon

Setting can be made with xrandr and by default the intel its always use to render, due the out source are set to display VGA screen:

glxinfo | grep "OpenGL renderer"
OpenGL renderer string: Mesa DRI Intel(R) Haswell Mobile x86/MMX/SSE2

Using the xrandr command u can activate the availibility of by set and asociation to the second provider and then using the variable DRI_PRIME, but also the screen source out must be set:

xrandr --setprovideroffloadsink 1 0
DRI_PRIME=0 glxinfo | grep "OpenGL renderer"
 OpenGL renderer string: Mesa DRI Intel(R) Haswell Mobile x86/MMX/SSE2
DRI_PRIME=1 glxinfo | grep "OpenGL renderer"
 OpenGL renderer string: Gallium 0.4 on AMD HAINAN

Manage by propietary way: using AMD and modeset

Support for AMD Ati HD 7XXXM and 8XXXM series was added since fglrx 13, so in Devuan need enabling non-free repositories, an due versions are enough above 12 standard non-free repositories are enough to install it.

The modesetting are needed and seem need explicit enabled, so use the modprobe.d files to do CAUTION: the echo must be do only one time:

echo "options i915 modeset=1" >> /etc/modprobe.d/modesetting.conf
echo "options radeon modeset=1" >> /etc/modprobe.d/modesetting.conf

By using acpi_call module (apt-get instal acpi-call-dkms) u can manage and complete off cards to complety save the power batery, this due many issues are reported when using the fglrx AMD software modules.

THE AMD FGLRX SOFTWARE WAS NOT TESTED COMPLETY

Power

Battery info are not recovered at all, the Linux kernel and acpi software are unable to calculate the amount of time of remaining load or charge, event discharge time.

The acpitool command does not offer right info so any pannel addon will always said “calculating” respect the time of discharge.

acpitool -B
Battery #1     : present
  Remaining capacity : unknown, 78.57%, 00:00:00
  Design capacity    : 6000 mA
  Last full capacity : 5128 mA, 85.47% of design capacity
  Capacity loss      : 14.53%
  Present rate       : 27 mA
  Charging state     : Discharging
  Battery type       : Li-ion 
  Model number       : DELL
  Serial number      : DA37

Keyboard

Keyboard are detected property, special keys are performed by mayor desktop, for light desktops flavors must fine tune. Added to the kernel command line in grub at boot or in grub.conf kernel start line:

acpi_osi=Linux acpi_backlight=vendor

This make it works event if no mayor desktops are installed, due make it works independent of.

CardReader

The buil in card reader not need any extra tune parameters and the Devuan after install performs good the manage of it.

Recommendations

a) have two GPU, Intel and AMD/ati, at today its bets for performance stability use only the Intel b) if u use as station and dont travel with the laptop use only the Ati card, if you will make travels, use only the Intel c) not recommended for development coding purposes d) good for view movies and play sounds e) not tested well on games and emulators.. advanced games perform well but not complete plenny