Commit 9a758d87 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm: Move nomodeset kernel parameter to drivers/video 



Move the nomodeset kernel parameter to drivers/video to make it
available to non-DRM drivers. Adapt the interface, but keep the DRM
interface drm_firmware_drivers_only() to avoid churn within DRM. The
function should later be inlined into callers.

The parameter disables any DRM graphics driver that would replace a
driver for firmware-provided scanout buffers. It is an option to easily
fallback to basic graphics output if the hardware's native driver is
broken. Moving it to a more prominent location wil make it available
to fbdev as well.

v2:
	* clarify the meaning of the nomodeset parameter (Javier)

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221111133024.9897-2-tzimmermann@suse.de
parent 27c3e945

Documentation/admin-guide/kernel-parameters.txt

+9 −6
Original line number Diff line number Diff line
@@ -3777,12 +3777,15 @@ 
			shutdown the other cpus.  Instead use the REBOOT_VECTOR

			irq.



	nomodeset	Disable kernel modesetting. DRM drivers will not perform

			display-mode changes or accelerated rendering. Only the

			system framebuffer will be available for use if this was

			set-up by the firmware or boot loader.



			Useful as fallback, or for testing and debugging.

	nomodeset	Disable kernel modesetting. Most systems' firmware

			sets up a display mode and provides framebuffer memory

			for output. With nomodeset, DRM and fbdev drivers will

			not load if they could possibly displace the pre-

			initialized output. Only the system framebuffer will

			be available for use. The respective drivers will not

			perform display-mode changes or accelerated rendering.



			Useful as error fallback, or for testing and debugging.



	nomodule	Disable module load

MAINTAINERS

+2 −0
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@@ -6701,8 +6701,10 @@ F: drivers/gpu/drm/drm_aperture.c 
F:	drivers/gpu/drm/tiny/ofdrm.c

F:	drivers/gpu/drm/tiny/simpledrm.c

F:	drivers/video/aperture.c

F:	drivers/video/nomodeset.c

F:	include/drm/drm_aperture.h

F:	include/linux/aperture.h

F:	include/video/nomodeset.h









DRM DRIVER FOR SIS VIDEO CARDS









S:	Orphan / Obsolete
































drivers/gpu/drm/Kconfig



+1
−6






























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@@ -8,7 +8,6 @@







menuconfig DRM









	tristate "Direct Rendering Manager (XFree86 4.1.0 and higher DRI support)"









	depends on (AGP || AGP=n) && !EMULATED_CMPXCHG && HAS_DMA









	select DRM_NOMODESET









	select DRM_PANEL_ORIENTATION_QUIRKS









	select HDMI









	select FB_CMDLINE








@@ -19,6 +18,7 @@ menuconfig DRM







# gallium uses SYS_kcmp for os_same_file_description() to de-duplicate









# device and dmabuf fd. Let's make sure that is available for our userspace.









	select KCMP









	select VIDEO_NOMODESET









	help









	  Kernel-level support for the Direct Rendering Infrastructure (DRI)









	  introduced in XFree86 4.0. If you say Y here, you need to select








@@ -514,11 +514,6 @@ config DRM_EXPORT_FOR_TESTS







config DRM_PANEL_ORIENTATION_QUIRKS









	tristate



















# Separate option because nomodeset parameter is global and expected built-in









config DRM_NOMODESET









	bool









	default n



















config DRM_LIB_RANDOM









	bool









	default n
































drivers/gpu/drm/Makefile



+0
−1






























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@@ -72,7 +72,6 @@ drm-$(CONFIG_DRM_PRIVACY_SCREEN) += \







	drm_privacy_screen_x86.o









obj-$(CONFIG_DRM)	+= drm.o



















obj-$(CONFIG_DRM_NOMODESET) += drm_nomodeset.o









obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o



















#
































drivers/video/Kconfig



+4
−0






























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@@ -11,6 +11,10 @@ config APERTURE_HELPERS







	  Support tracking and hand-over of aperture ownership. Required









	  by graphics drivers for firmware-provided framebuffers.



















config VIDEO_NOMODESET









	bool









	default n



















if HAS_IOMEM



















config HAVE_FB_ATMEL