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 <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221111133024.9897-2-tzimmermann@suse.de
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
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
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
# 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
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
drm_privacy_screen_x86.o
obj-$(CONFIG_DRM) += drm.o
-obj-$(CONFIG_DRM_NOMODESET) += drm_nomodeset.o
obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o
#
Support tracking and hand-over of aperture ownership. Required
by graphics drivers for firmware-provided framebuffers.
+config VIDEO_NOMODESET
+ bool
+ default n
+
if HAS_IOMEM
config HAVE_FB_ATMEL
obj-$(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/
#include <linux/module.h>
#include <linux/types.h>
-static bool drm_nomodeset;
+#include <video/nomodeset.h>
-bool drm_firmware_drivers_only(void)
+static bool video_nomodeset;
+
+bool video_firmware_drivers_only(void)
{
- return drm_nomodeset;
+ return video_nomodeset;
}
-EXPORT_SYMBOL(drm_firmware_drivers_only);
+EXPORT_SYMBOL(video_firmware_drivers_only);
static int __init disable_modeset(char *str)
{
- drm_nomodeset = true;
+ video_nomodeset = true;
pr_warn("Booted with the nomodeset parameter. Only the system framebuffer will be available\n");
#include <linux/list.h>
#include <linux/irqreturn.h>
+#include <video/nomodeset.h>
+
#include <drm/drm_device.h>
struct drm_file;
int drm_dev_set_unique(struct drm_device *dev, const char *name);
-extern bool drm_firmware_drivers_only(void);
+/* TODO: Inline drm_firmware_drivers_only() in all its callers. */
+static inline bool drm_firmware_drivers_only(void)
+{
+ return video_firmware_drivers_only();
+}
#endif
--- /dev/null
+/* SPDX-License-Identifier: MIT */
+
+#ifndef VIDEO_NOMODESET_H
+#define VIDEO_NOMODESET_H
+
+bool video_firmware_drivers_only(void);
+
+#endif