Kernel: Linux 5.1, Linux 5.0, LVFS and Elisa
For those interested in using graphics drawing tablets on Linux, a number of devices will now be supported with the upcoming Linux 5.1 kernel cycle.
A number of updates are pending to the “uclogic” HID driver for supporting various UC-Logic graphics tablet devices. This work for Linux 5.1 includes supporting a new version of the company’s device protocol and going on to add support for the Ugee 2150, Ugee M540, XP-Pen Star G540, XP-Pen Star G640, XP-Pen Deco 01, and Ugee G5.
Last week I reported on some slowdowns when running on the Linux 5.0 development kernel for both Intel and AMD systems. As a few days passed and the regression didn’t seem to be figured out and addressed by upstream, and several inquiries from Phoronix readers, I spent some time looking at some of the slowdowns encountered when running on this bleeding-edge code.
The slowdowns when encountered so far on a few different systems were some of the most sizable regressions since the Linux 4.14 to 4.15 transition when Spectre and Meltdown mitigations began rolling out. But with the 5.0 regressions, they haven’t been across the board and range from a few percent to about 10% or so.
The fwupd project has supported updating the microcode on ATA devices for about a month, and StarLabs is shipping firmware on the LVFS already. More are coming, but as part of the end-to-end testing with various deliberately-unnamed storage vendors we hit a thorny issue.
Most drives require the firmware updater to use the so-called 0xE mode, more helpfully called ATA_SUBCMD_MICROCODE_DOWNLOAD_CHUNKS in fwupd. This command transfers chunks of firmware to the device, and then the ATA hardware waits for a COMRESET before switching to the new firmware version. On most drives you can also use 0x3 mode which downloads the chunks and switches to the new firmware straight away using ATA RESET. As in, your drive currently providing your root filesystem disconnects from your running system and then reconnects with the new firmware version running.
The project is called Elisa, for “Enabling Linux in Safety Applications,” and it’s aim is to create a shared set of tools and processes for building Linux-based systems that will operate without surprises in situations where failure could cause injury, loss of life, or result in significant property or environmental damage.
These days computers are being used to perform a long and growing list of tasks that can have serious consequences if something goes wrong. This includes light rail systems where the trains often drive themselves, robotic devices, medical devices, and smart factories where potentially dangerous tasks are directed by single board computers spitting out X’s and O’s.