Hi,
Am 06.06.26 um 16:49 schrieb Guilherme Bember Duarte:
Hi!
I replaced DRM_FBDEV_EMULATION with DRM_CLIENT_LOG
(DRM_CLIENT_DEFAULT="log") on a kernel with DRM_PANIC enabled, using
kmscon as the userspace terminal. Nothing initialises the display
after the native driver loads.
The result is a blank screen, no output at all from boot.
DRM_CLIENT_LOG (boot logs don't show up at all) and DRM_PANIC (forced
a panic to try this out) also don't work, since neither can render
without an initialised display.
This can be verified by checking "/sys/class/drm/card0-*/status" (all
outputs show "unknown") and "/sys/class/drm/card0-*/modes" (empty)
after boot.
Writing "detect" to "/sys/class/drm/card0-HDMI-A-1/status" (or any
output for that matter) resolves the issue, the connector is probed,
modes are populated, and kmscon can be started correctly. This
suggests DRM_FBDEV_EMULATION previously triggered some display
initialisation/probing during boot that is not happening with
DRM_CLIENT_LOG.
I can't say if SIMPLEDRM (and SIMPLEFB) are affected, the result in my
system is a immediate blank screen and no signal, I don't know if its
because the main graphics driver initialise very quickly during boot
or if SIMPLEDRM is also affected.
Did you boot with "console=drm_log" at the kernel command line?
Best regards
Thomas
Hardware: AMD RX 6600 XT (Navi23/AMDGPU), although I believe this
affects any driver.
Kernel version: 7.0.11-gentoo
Config diff:
2849a2850
> # CONFIG_VGA_SWITCHEROO is not set
2874,2879c2875,2878
< CONFIG_DRM_FBDEV_EMULATION=y
< CONFIG_DRM_FBDEV_OVERALLOC=100
< # CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM is not set
< # CONFIG_DRM_CLIENT_LOG is not set
< CONFIG_DRM_CLIENT_DEFAULT_FBDEV=y
< CONFIG_DRM_CLIENT_DEFAULT="fbdev"
------------------------------------------------------------------------
> # CONFIG_DRM_FBDEV_EMULATION is not set
> CONFIG_DRM_CLIENT_LOG=y
> CONFIG_DRM_CLIENT_DEFAULT_LOG=y
> CONFIG_DRM_CLIENT_DEFAULT="log"
2978,2986d2976
< CONFIG_FB_CORE=y
< # CONFIG_FB_DEVICE is not set
< CONFIG_FB_SYS_FILLRECT=y
< CONFIG_FB_SYS_COPYAREA=y
< CONFIG_FB_SYS_IMAGEBLIT=y
< CONFIG_FB_SYSMEM_FOPS=y
< CONFIG_FB_DEFERRED_IO=y
< CONFIG_FB_SYSMEM_HELPERS=y
< CONFIG_FB_SYSMEM_HELPERS_DEFERRED=y
3021,3024d3010
< CONFIG_FRAMEBUFFER_CONSOLE=y
< # CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION is not set
< CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY=y
< # CONFIG_FRAMEBUFFER_CONSOLE_ROTATION is not set
3027d3012
< # CONFIG_LOGO is not set
4473d4457
< # CONFIG_FONT_SUN8x16 is not set
Guilherme B.
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)
