Alexandre Oliva, the project leader, wrote in the release log: “The major piece of news in this release is that the request_firmware machinery was slightly reworked, so that (i) the reject_firmware variants return the expected -ENOENT, instead of -EINVAL; and (ii) reject_firmware_nowait now calls the named callback. With this, drivers that could proceed without firmware, but that failed because of -EINVAL, or because they did so in the nowait callback, should now work more seamlessly. Some radeon-controlled video cards for which we hadn’t put in work-arounds might start working now (no promises, but if you find out such a card starts working again, that’s why). Another example that is likely to start working due to this change is rtl8821ae cards: I got a report that at least some such cards would work even when the firmware loading failed, and these used _nowait. That’s what prompted me to make this chnage. Thanks to temy on FreeNode for the report..”
Thanks to this change, various AMD Radeon graphics drivers are working again, and more importantly, the GNU Linux-Libre 4.16 kernel version removes the recommendation of users to upgrade to Intel x86 CPU microcode (non-freeware).
