kern/54976: radeon framebuffer fails initialization in NetBSD-9

[rcbixler%nyx.net@localhost]

>Number:         54976
>Category:       kern
>Synopsis:       radeon framebuffer fails initialization in NetBSD-9
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Feb 17 16:00:00 +0000 2020
>Originator:     Roy Bixler
>Release:        NetBSD-9
>Organization:
>Environment:
NetBSD localhost 9.0 NetBSD 9.0 (GENERIC) #0: Fri Feb 14 00:06:28 UTC 2020  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64
>Description:
Lenovo Thinkpad with AMD Radeon fails to boot by default due to a failure to initialize the framebuffer.  The failure appears to be related to an abortive attempt to load a microcode file called "radeon/kaveri_mec2.bin".
>How-To-Repeat:
boot the laptop either with a standard NetBSD-9 installation image via USB stick or with the standard GENERIC kernel.
>Fix:
Comment out the following block starting around line 2187 in /usr/src/sys/external/bsd/drm2/dist/drm/radeon/radeon_cik.c:

	/*
	if (rdev->family == CHIP_KAVERI) {
		snprintf(fw_name, sizeof(fw_name), "radeon/%s_mec2.bin", new_chip_name);
		err = request_firmware(&rdev->mec2_fw, fw_name, rdev->dev);
		if (err) {
			goto out;
		} else {
			err = radeon_ucode_validate(rdev->mec2_fw);
			if (err) {
				goto out;
			} else {
				new_fw++;
			}
		}
	}
	*/