Linux on Asus R541U

    This is my experience with openSUSE Linux LEAP 15.2 on the Asus R541UA-RS51 laptop.  (Note: memtest identifies this computer as X541UAK / U3E1.)  Things in parenthesis are what Windows reports with Device Manager.  See previous versions OpenSuSE 42.3 or openSUSE LEAP 15.0 or openSUSE LEAP 15.1.

Hardware Components
Status under Linux
Intel Core i5-7200UProcessor 2.5GHz (up to 3.1GHz) 3M Cache Works

Display: BOE 15.6inch FHD (1920 x 1080) Works
I specify 141 DPI in XFCE
Intel HD graphics 620

8GB DDR4 RAM Works
Toshiba 1TB 5400RPM Hard Drive
Works Upgraded to Seagate Hybrid Laptop 1TB
Realtek RTS5286 PCI Express Card Reader (for SD cards)

DVD Drive: 8X Super Multi w/ DL ("HL-DT-ST DVD-RAM")

Realtek RTL8723BE PCIe Wireless Network Adapter

IMC Networks Video Cam ("VGA UVC Webcam")

USB: one 3.0, one 2.0, and one USB-C 3.1 port
Fast charge works even with stock kernel.
36WHrs 3-cell Li-ion Battery Pack Works
Provides roughly 4 hrs
Intel High Def. Audio  9d71 (rev 21) Realtech ALC256
ELAN Touchpad ("Asus Precision")

Realtek RTL8101/2/6E PCIE Fast/Gigabit Ethernet controller

Asus keyboard
Works; slight nuisance
Number lock keeps engaging; no on-screen status program
Realtech Bluetooth 4.0
Works Works better than ever in OpenSUSE LEAP 15.2.
Intel Sunrise Chipset, Power Management

Physical Fit and Finish

    Please see the first article on openSUSE 42.3 for how to upgrade the hard drive.

Installation of OpenSUSE LEAP 15.2

    Installation was easy.  As well, for the first time, network-based installation worked.  But I had to make sure I gave the installer the pci=noaer option at boot.  To do this, I pressed C (I think) to edit the command line, and then after the /path/to/linux, I added that option, then told Grub (from the install DVD) to boot.
    I noticed that while the installer has gotten a lot smarter, such as allowing you to move old fstab and other configurations over, it does not let you specify tmpfs mount points such as /tmp.  More about this in the next section.

Using OpenSUSE LEAP 15.2

    First, I noticed that my logs filled up with error messages similar to these about AER ePCI errors.  Adding pci=noaer to the kernel command line seemed to fix that.  Note that you must specify this option when you boot the install media for 15.1, as well as when you set the boot options during the install process. If you don't, your logs will fill up too fast and you'll crash your system, or things will start randomly not writing to disk.  My first time, I didn't specify this (you think, given previous articles, I would've learned by now) and locale service broke, breaking many other things and rendering my system unusable.  So learn from my lesson: specify this option right from the beginning.

    Second, note that now you can have a fully encrypted hard drive, if you don't mind giving GRUB2 your LUKS password for your encrypted boot folder, then again to LUKS to unlock the rest of your partitions.  At first, this threw me off, until I realized I had not specified /dev/sda6 as my /boot during the install, like other times.  So it's worth noting that this is possible.  But I don't like entering the same password twice, so for now, I just fixed my mistake and set up my boot partition.

    Note that the speakers on this laptop are very loud and sound great, in general.
    As for USB support, note that there's a 2.0, 3.0, and 3.1 port.  The USB 2.0 port is nearest the laptop user.  Fast charging a cell phone with USB-C works even in Linux, but it requires you to use a USB-C to USB-C cable from the 3.1 port to your cell phone.  When you do this, it "just works", without any configuration required.  The power outputs seem to be dependent upon system state: i.e. if the laptop is on, USB-C power outputs are always on, and thus will fast charge any USB-C device that supports this.  There's still, apparently, no application to control this.
    My solution for using two USB hard drives at the same time (due to having a 3.0 and 2.0 port) is to use a USB-C to 3.0 adapter and then putting the two hard drives on 3.0 ports.  I tend to reserve the 2.0 port for a USB mouse or something that has low data usage.
    In previous versions, Bluetooth took a lot of configuration.  Now it works right out of the box.  So does phone tethering, something that absolutely refused to work in Leap 15.1 and previous versions.

Annoying Behavior on OpenSUSE LEAP 15.2

    The keyboard has a hybrid laptop/desktop layout with a numeric keyboard section.  However, the end key is on the numeric portion.  When typing, the number lock comes on, causing the end key to function as a "1".  I am constantly turning off the number lock in OpenSUSE, even in the new kernel, and even though I've configured the keyboard models and such.  It's been this way since my previous installations of openSUSE as well.  Also, there's no on-screen application for XFCE that I can find that will display the status of the number lock on screen.  In addition, I have set "no" or "off" to the only number lock related setting in the sysconfig editor, and that results in the computer booting up with the number lock off, but eventually it will come back on by itself.
    The tmpfs partitions are back to needing to be told (for /dev/shm and others) to only use 512mb.  I had my swap partition fill up dramatically prior to specifying this.  So it's back to needing work.  I wish there was a way to tell OpenSUSE LEAP that I'm using a laptop, so that it is more conservative with the size of tmpfs mounts.  People can claim that the Linux kernel moves memory around to compensate for things, but my experience with the tmpfs debacle is that these regions of memory seem less flexible and more set in stone once they're mounted, in terms of memory use.  If I force some of these mount points to remount upon boot to a smaller tmpfs size, I don't dig into swap nearly as much.  And in my opinion, using tmpfs for /dev structures is wasteful of RAM anyways, but I digress.

    But with the advent of openSUSE LEAP 15.1, you can't specify tmpfs during installation, which is very annoying.  To manually make your own (WARNING: if you don't know what you're doing, you could break your system!), do this in a terminal as root when you finally boot for the first time.  This "moves over" everything from /tmp to a tmpfs /tmp.  I like this because I tend to use /tmp for secure file storage for temporary purposes.  If an emergency happens (stolen laptop, panic press of power button, etc), whatever file it was is gone forever.  Not to mention I encrypt my hard drive as well, but I digress....

cd /
mv tmp tmp2
mkdir tmp
chmod 1777 tmp
echo "tmpfs /tmp tmpfs rw,nodev,nosuid,size=512m 0 0" >> /etc/fstab
mount /tmp
mv * /tmp
mv .[A-Z]* /tmp
cd /
rmdir /tmp2