From 9a758d8756daab5b8fda006e131c066336b16a32 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Fri, 11 Nov 2022 14:30:23 +0100 Subject: [PATCH] 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 --- Documentation/admin-guide/kernel-parameters.txt | 13 ++++++++----- MAINTAINERS | 2 ++ drivers/gpu/drm/Kconfig | 7 +------ drivers/gpu/drm/Makefile | 1 - drivers/video/Kconfig | 4 ++++ drivers/video/Makefile | 1 + .../{gpu/drm/drm_nomodeset.c => video/nomodeset.c} | 12 +++++++----- include/drm/drm_drv.h | 8 +++++++- include/video/nomodeset.h | 8 ++++++++ 9 files changed, 38 insertions(+), 18 deletions(-) rename drivers/{gpu/drm/drm_nomodeset.c => video/nomodeset.c} (63%) create mode 100644 include/video/nomodeset.h diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index a465d5242774..88561b3ce28a 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. + 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 fallback, or for testing and debugging. + Useful as error fallback, or for testing and debugging. nomodule Disable module load diff --git a/MAINTAINERS b/MAINTAINERS index 178a7a383b5f..7dc3b719b2a2 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 34f5a092c99e..722ded626399 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 c44a54cadb61..f92cd7892711 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/video/Kconfig b/drivers/video/Kconfig index 0587e21abad9..6d2fde6c5d11 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 5bb6b452cc83..a50eb528ed3c 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/gpu/drm/drm_nomodeset.c b/drivers/video/nomodeset.c similarity index 63% rename from drivers/gpu/drm/drm_nomodeset.c rename to drivers/video/nomodeset.c index f3978d5bd3a1..13cc8b719697 100644 --- a/drivers/gpu/drm/drm_nomodeset.c +++ b/drivers/video/nomodeset.c @@ -3,17 +3,19 @@ #include #include -static bool drm_nomodeset; +#include