Kernel config options for drm [ Was Re: No HDMI output... ]

[Mayuresh <mayuresh%acm.org@localhost>]

On Mon, Dec 26, 2022 at 10:01:32PM +0530, Mayuresh wrote:
> # dmesg | grep -i -e Radeon -e drm
> [     1.000004] cpu0: AMD A6-9225 RADEON R4, 5 COMPUTE CORES 2C+3G   , id 0x670f00
> [     1.000004] cpu1: AMD A6-9225 RADEON R4, 5 COMPUTE CORES 2C+3G   , id 0x670f00
> [     1.047740] genfb0 at pci0 dev 1 function 0: ATI Technologies Radeon R2/R3/R4/R5 Graphics (rev. 0xea)
> [     1.047740] drm at genfb0 not configured
> 
> Please suggest whether a kernel reconfiguration is required for HDMI to
> work.

To be more specific:

    # config -x | grep drm
    #i915drm*       at drm?         # Intel i915, i945 DRM driver
    #mach64drm*     at drm?         # mach64 (3D Rage Pro, Rage) DRM driver
    #mgadrm*        at drm?         # Matrox G[24]00, G[45]50 DRM driver
    #r128drm*       at drm?         # ATI Rage 128 DRM driver
    #radeondrm*     at drm?         # ATI Radeon DRM driver
    #savagedrm*     at drm?         # S3 Savage DRM driver
    #sisdrm*        at drm?         # SiS DRM driver
    #tdfxdrm*       at drm?         # 3dfx (voodoo) DRM driver
    i915drmkms*     at pci? dev ? function ?
    radeondrmkmsfb* at radeonfbbus?
    #viadrmums*     at drm?


i915drm is disabled, but i915drmkms is enabled. Similarly radeondrm is
disabled and radeondrmkmsfb is enabled. What does this exactly mean?

Also, how to interpret the message "drm at genfb0 not configured".

    # config -x | grep genfb
    # enable splash screen support; requires genfb or radeonfb
    genfb*          at pci? dev ? function ?
    genfb*          at vmbus?               # Hyper-V Synthetic Video Framebuffer



-- 
Mayuresh