How I failed at installing Linux on a new laptop
My Dell Mini-9 (also known as the Inspiron 901) laptop is now 10 years old. It came with a 1.6 GHz Atom processor, 512M of memory, an 8GB SSD, and Ubuntu preinstalled. I upgraded the memory to 2GB a few years after I got it, and it's been my travel laptop the entire time I've owned it. But its battery died about two years ago, and its SSD is no longer large enough to allow Ubuntu to upgrade to the latest versions. A new battery and adding a 16GB SD card returned the unit to usability, but it has become obvious that it is time for a replacement.
Dell no longer offers any Inspiron laptops with Linux preinstalled (their Linux preinstalled laptops are the XPS series and since they start at $779, they're well outside my price range), but historically their laptops have been fairly Linux friendly. When I found the Inspiron 11" 3000 series on sale last year for $150 it looked like it might be the ideal replacement. So I hopefully ordered one.
This laptop comes with an AMD E2-9000e processor with Radeon R2 graphics, 4GB of memory, a 32GB eMMC drive, and Windows 10 Home preinstalled. It has one USB 2 port, one USB 3 port, an HDMI video port, and a slot for a micro-SD card. Getting it with Linux was not an option, nor is there an option to download a Linux bootable iso for it, though curiously both the system setup guide and the service manual list Linux as a supported operating system. It is officially an Inspiron 3180, Reg model P24T, Reg Type No P24T003. Its small size and light weight make it an ideal travel laptop.
Windows 10 runs slowly on this machine, but is adequate for browsing the web while travelling. Its main problem is that the 32GB drive is not large enough to allow feature updates to install. To install an update you have to save it to an external drive, run it from there, and add yet another drive for extra storage during the installation. Given the way Windows installations tend to grow over time, it's obvious that Windows 10 will eventually outgrow the internal hard drive and become unusable. Linux would obviously be a much better operating system for this machine, as the 32GB drive should be more than adequate. Why Dell doesn't offer it as an order option is beyond me.
So I prepared a Linux Mint bootable USB drive for testing. My goal was to install Linux on an SD card in the machine and keep the Windows 10 drive intact for now, thus allowing for a dual boot option. And I immediately ran into problems. Linux Mint (at that time 19.0) would not boot from the USB 3 port. It would boot from the USB 2 port, so that's what I used. But once it was booted, it could not access the SD card. From memory, it could not access the internal drive either. Everything else seemed to work properly, including the wireless chipset.
The performance was impressive, but with the SD card not being accessible the only option was to boot from the USB drive and run Linux Mint as a live USB system. I've used it that way since, only booting into Windows when my wife wanted to use it and to install updates. Since that time Linux Mint has upgraded to 19.1, based on Ubuntu 18.04. So I upgraded my USB drive to 19.1 and tried again.
I never had a problem booting from the USB 2 port with the 19.0 version of Linux Mint, but with 19.1, the boot up is finicky. A cold boot seems to work most of the time, but sometimes the boot will hang on the Linux Mint screen, and on occasion the touchpad will not work once it's booted. The good news is that it will now boot from both the USB 2 and USB 3 ports and that it can now read the eMMC drive. The bad news is that the SD card is still not working. I get similar results booting from a Slackware-current live USB drive.
Research on this problem reveals that the Inspiron 3180 and most others in that series are using the Realtek RTS5139 chipset and support for that chipset has apparently been broken since the 3.16 kernel days. The current rtsx driver simply doesn't support that chipset. See https://github.com/asymingt/rts5139 for the gory details. So while installing Linux Mint on an SD card on this machine should be possible, doing so would involve compiling a kernel module and blacklisting the current driver. That's not something I'm willing to undertake at this time.
Whether it would be possible to overwrite the current Windows 10 installation and install Linux on the internal eMMC drive is an open question. This article https://ansuz.sooke.bc.ca/entry/340 dealing with an Inspiron 3162 indicates that the Slackware installer will have issues. But various posts on the Ubuntu and Linux Mint forums indicate that if you disable "secure boot" and "allow legacy roms" in the bios they should install successfully.
This laptop apparently does have an option for a SATA drive, but the SATA connector is apparently not installed on the motherboard. And while it has an M.2 connector, it is used for the bluetooth/wireless chipset. So upgrading to a SATA or M.2 drive really isn't an option. So until I can find time to fiddle with the kernel or decide to blow away the Windows installation completely, I'll continue booting this machine from an external USB drive and using it that way.
Posted in the hopes that others may find it informative or useful.