Dell Inspiron 3531
This page describes Arch's issues with Dell Inspiron 15 3531 (budget model of autumn 2014).
Hardware Specifications
This cheap stripped down model has:
- no optical drive (and, although there is a slot for the drive, the motherboard has no SATA connector),
- no Bluetooth,
- no CPU fan,
- no external microphone jack
- no Ethernet (RJ45) jack.
lspci Output
00:00.0 Host bridge: Intel Corporation Atom Processor Z36xxx/Z37xxx Series SoC Transaction Register (rev 0e) 00:02.0 VGA compatible controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Graphics & Display (rev 0e) 00:13.0 SATA controller: Intel Corporation Device 0f23 (rev 0e) 00:1a.0 Encryption controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Trusted Execution Engine (rev 0e) 00:1b.0 Audio device: Intel Corporation Atom Processor Z36xxx/Z37xxx Series High Definition Audio Controller (rev 0e) 00:1c.0 PCI bridge: Intel Corporation Device 0f48 (rev 0e) 00:1c.1 PCI bridge: Intel Corporation Device 0f4a (rev 0e) 00:1c.2 PCI bridge: Intel Corporation Device 0f4c (rev 0e) 00:1c.3 PCI bridge: Intel Corporation Device 0f4e (rev 0e) 00:1d.0 USB controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series USB EHCI (rev 0e) 00:1f.0 ISA bridge: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Power Control Unit (rev 0e) 00:1f.3 SMBus: Intel Corporation Device 0f12 (rev 0e) 02:00.0 Network controller: Qualcomm Atheros AR9485 Wireless Network Adapter (rev 01)
lsusb Output
Bus 001 Device 005: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller Bus 001 Device 004: ID 0bda:58c2 Realtek Semiconductor Corp. Bus 001 Device 002: ID 8087:07e6 Intel Corp. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Installation in MBR mode
The only installation method possible on this computer is from a USB key. Create one following this page.
In the following the MBR booting mode is assumed (UEFI boot mode was not tested). To turn on the Legacy BIOS boot mode (aka MBR) in the BIOS menu, press F2 at startup. Set secure boot to off and set boot list order to legacy. Also change function keys from the multimedia mode.
Kernel
The standard Arch kernel works fine.
Video artifacts at boot
After the GRUB menu a first couple of lines are garbage. To remedy
add to /etc/mkinitcpio.conf
the line
/etc/mkinitcpio.conf
... MODULES="i915" ...
and run
# mkinitcpio -p linux
Hardware
Video
Install the xf86-video-intel driver.
HDMI output
Works out of the box (tested under XFCE)
Input
Touchpad
Install the xf86-input-synaptics driver.
Hypersensity of the touchpad can be reduced by editing /etc/X11/xorg.conf.d/50-synaptics.conf
/etc/X11/xorg.conf.d/50-synaptics.conf
... Section "InputClass" Identifier "touchpad catchall" .... Option "FingerLow" "35" <-- add this Option "FingerHigh" "45" <-- add this .... EndSection ...
Tune the values to your taste (increasing reduces sensitivity).
SD card reader
The laptop has an RTS5129 controller which is now handled by modules
rtsx_usb
and rtsx_usb_sdmmc
. To enable permanently create a file /etc/modules-load.d/sdcard.conf
with two lines:
/etc/modules-load.d/sdcard.conf
rtsx_usb rtsx_usb_sdmmc
Networking
Wired
Works out of the box through a USB-to-Ethernet adaptor.
Wireless
Atheros AR9485 works out of the box. network-manager-applet was used to manage networks.
3G USB Modem
A test device Huawei E173s 3G USB modem was detected and worked fine with network-manager-applet, modem-manager-gui, usb_modeswitch and mobile-broadband-provider-info packages.
Audio
Built-in microphone does not work out of the box. To enable,
create a file /etc/modeprobe.d/modeprobe.conf
with a line
/etc/modeprobe.d/modeprobe.conf
options snd-hda-intel model=laptop
and unmute microphones in alsamixer (press M
on devices with an MM
annotation).
Backlight (and XFCE)
For those with sensitive eyes the default handling of backlight in XFCE can be troublesome. The range of the intel_backlight on this laptop is 7812 steps, however xfce4-power-manager uses only hardcoded 10 steps what might be too coarse. Adding
acpi_backlight=vendor
to the kernel parameters creates /sys/class/backlight/dell_backlight/
with max_brightness=15
, and power-manager now steps with 20% of it (3 points), which may also be suboptimal.
The usual workaround to assign commands xbacklight +5
and xbacklight -5
to the function keys Fn+F5/F4
(using Settings->Keyboard) to finer-grained control does not solve the problem, because the power manager intercepts keystrokes.
Disabling the brightness keys in the power manager AND enabling the above keyboard shortcuts somehow works (decreasing brightness and increasing it again does not always give you the same number). Test it to see if you are fine with such a behavior.
Finest grained control of the backlight can be achieved with the direct setting
# echo 100 | tee /sys/class/backlight/intel_backlight/brightness
(change 100 to your number of choice). To complicate things even more, this value is not saved after reboot if it's less than 390, because systemd is hardcoded to have at least 5% of max_brightness at start-up. If your favorite brightness is below 390, the only way is to run this number on every boot.