From: Thomas Zimmermann Date: Fri, 11 Nov 2022 13:30:23 +0000 (+0100) Subject: drm: Move nomodeset kernel parameter to drivers/video X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9a758d8756daab5b8fda006e131c066336b16a32;p=linux.git 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: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20221111133024.9897-2-tzimmermann@suse.de --- diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index a465d5242774a..88561b3ce28a4 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -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 diff --git a/MAINTAINERS b/MAINTAINERS index 178a7a383b5fc..7dc3b719b2a24 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -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 diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 34f5a092c99e7..722ded6263991 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -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 diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index c44a54cadb618..f92cd78927110 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -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 # diff --git a/drivers/gpu/drm/drm_nomodeset.c b/drivers/gpu/drm/drm_nomodeset.c deleted file mode 100644 index f3978d5bd3a1d..0000000000000 --- a/drivers/gpu/drm/drm_nomodeset.c +++ /dev/null @@ -1,24 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 - -#include -#include - -static bool drm_nomodeset; - -bool drm_firmware_drivers_only(void) -{ - return drm_nomodeset; -} -EXPORT_SYMBOL(drm_firmware_drivers_only); - -static int __init disable_modeset(char *str) -{ - drm_nomodeset = true; - - pr_warn("Booted with the nomodeset parameter. Only the system framebuffer will be available\n"); - - return 1; -} - -/* Disable kernel modesetting */ -__setup("nomodeset", disable_modeset); diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 0587e21abad94..6d2fde6c5d11a 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -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 diff --git a/drivers/video/Makefile b/drivers/video/Makefile index 5bb6b452cc83a..a50eb528ed3c3 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_APERTURE_HELPERS) += aperture.o obj-$(CONFIG_VGASTATE) += vgastate.o +obj-$(CONFIG_VIDEO_NOMODESET) += nomodeset.o obj-$(CONFIG_HDMI) += hdmi.o obj-$(CONFIG_VT) += console/ diff --git a/drivers/video/nomodeset.c b/drivers/video/nomodeset.c new file mode 100644 index 0000000000000..13cc8b7196978 --- /dev/null +++ b/drivers/video/nomodeset.c @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +#include