For those that like to make remarks about AMD “fine wine” especially when it comes to open-source Linux drivers and/or nostalgic about feature work on really old hardware, to much amusement there are new patches today for the AMD InterWave ISA sound card from the 1990s.
While the Linux kernel is preparing to phase out its Intel 486 CPU support as Phoronix noted a few days ago, for some old but slightly newer vintage hardware driver activity is new feature work on the AMD InterWave sound card driver. The AMD InterWave sound card was based on the Gravis UltraSound “GUS” sound card IP. The AMD AM78C201(A)KC was impressive, back in the 1990s.
An AMD InterWave Gravis UltraSound driver was written for the Linux kernel back in the 1990s albeit rarely touched in the past two decades. Most of the AMD InterWave driver (interwave.c) changes since 2005 when the Linux kernel was imported to Git have just been common ALSA changes. There has been the occasional code adaptation to the GUS drivers for using more modern functions and the like but nothing really noteworthy for these ISA-based sound cards that are long obsolete.
So it was to much surprise when seeing today that this patch series came about from an open-source developer to provide suspend and resume support for InterWave ISA sound cards. Developer Cássio Gabriel remarked:
“This 3-patch series wires up suspend and resume support for the InterWave ISA drivers and their PnP front-end around the shared GUS PM helpers.
The first patch moves the remaining standalone snd_tea6330t_detect() EXPORT_SYMBOL() declaration next to its function definition as a requested small cleanup.
The second patch adds a small TEA6330T helper so the InterWave STB variant can restore its cached external mixer state after resume.
The third patch adds ISA and PnP PM callbacks to snd-interwave and restores the remaining InterWave-specific state that the generic GUS resume path does not cover, including the GF1 board registers and the detected memory layout.”
Actual feature work — enabling suspend and resume compatibility — for the AMD InterWave ISA sound driver. In 2026. Just under 200 lines of code were needed for making this driver friendly with suspend/resume.
