[PATCH v3 2/3] fbdev: Split frame buffer support in FB and FB_CORE symbols
From: Javier Martinez Canillas <javierm@redhat.com>
Date: 2023-07-02 19:17:23
Also in:
dri-devel, lkml
Subsystem:
console subsystem, framebuffer core, framebuffer layer, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Greg Kroah-Hartman, Simona Vetter, Helge Deller, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Currently the CONFIG_FB option has to be enabled even if no legacy fbdev drivers are needed (e.g: only to have support for framebuffer consoles). The DRM subsystem has a fbdev emulation layer, but depends on CONFIG_FB and so it can only be enabled if that dependency is enabled as well. That means fbdev drivers have to be explicitly disabled if users want to enable CONFIG_FB, only to use fbcon and/or the DRM fbdev emulation layer. This patch introduces a non-visible CONFIG_FB_CORE symbol that could be enabled just to have core support needed for CONFIG_DRM_FBDEV_EMULATION, allowing CONFIG_FB to be disabled (and automatically disabling all the fbdev drivers). Nothing from fb_backlight.o and fbmon.o is used by the DRM fbdev emulation layer so these two objects can be compiled out when CONFIG_FB is disabled. Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> --- Changes in v3: - Really make a hidden symbol by removing the prompt (Arnd Bergmann). - Change FB_CORE to config instead of menuconfig (Arnd Bergmann). - Keep "depends on FB" for FIRMWARE_EDID (Arnd Bergmann). - Compile out fb_backlight.o and fbmon.o that are only needed for FB (Arnd Bergmann). - Make FB_DEVICE to depend on FB_CORE instead of selecting it. Changes in v2: - Keep "depends on FB" for FB_DDC, FB_HECUBA, FB_SVGALIB, FB_MACMODES, FB_BACKLIGHT, FB_MODE_HELPERS and FB_TILEBLITTING (Arnd Bergmann). - Don't change the fb.o object name (Arnd Bergmann). - Make FB_CORE a non-visible Kconfig symbol instead (Thomas Zimmermann). arch/x86/Makefile | 2 +- arch/x86/video/Makefile | 2 +- drivers/video/console/Kconfig | 2 +- drivers/video/fbdev/Kconfig | 40 +++++++++++++++++++------------ drivers/video/fbdev/core/Makefile | 8 +++---- 5 files changed, 32 insertions(+), 22 deletions(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index b39975977c03..89a02e69be5f 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile@@ -259,7 +259,7 @@ drivers-$(CONFIG_PCI) += arch/x86/pci/ # suspend and hibernation support drivers-$(CONFIG_PM) += arch/x86/power/ -drivers-$(CONFIG_FB) += arch/x86/video/ +drivers-$(CONFIG_FB_CORE) += arch/x86/video/ #### # boot loader support. Several targets are kept for legacy purposes
diff --git a/arch/x86/video/Makefile b/arch/x86/video/Makefile
index 11640c116115..5ebe48752ffc 100644
--- a/arch/x86/video/Makefile
+++ b/arch/x86/video/Makefile@@ -1,2 +1,2 @@ # SPDX-License-Identifier: GPL-2.0-only -obj-$(CONFIG_FB) += fbdev.o +obj-$(CONFIG_FB_CORE) += fbdev.o
diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
index a2a88d42edf0..1b5a319971ed 100644
--- a/drivers/video/console/Kconfig
+++ b/drivers/video/console/Kconfig@@ -72,7 +72,7 @@ config DUMMY_CONSOLE_ROWS config FRAMEBUFFER_CONSOLE bool "Framebuffer Console support" - depends on FB && !UML + depends on FB_CORE && !UML select VT_HW_CONSOLE_BINDING select CRC32 select FONT_SUPPORT
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index cecf15418632..d436a4fd6f0a 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig@@ -6,10 +6,14 @@ config FB_NOTIFY bool +config FB_CORE + select VIDEO_CMDLINE + tristate + menuconfig FB - tristate "Support for frame buffer devices" + tristate "Support for frame buffer device drivers" + select FB_CORE select FB_NOTIFY - select VIDEO_CMDLINE help The frame buffer device provides an abstraction for the graphics hardware. It represents the frame buffer of some video hardware and
@@ -33,6 +37,12 @@ menuconfig FB <http://www.munted.org.uk/programming/Framebuffer-HOWTO-1.3.html> for more information. + This enables support for native frame buffer device (fbdev) drivers. + + The DRM subsystem provides support for emulated frame buffer devices + on top of KMS drivers, but this option allows legacy fbdev drivers to + be enabled as well. + Say Y here and to the driver for your graphics board below if you are compiling a kernel for a non-x86 architecture.
@@ -59,7 +69,7 @@ config FIRMWARE_EDID config FB_DEVICE bool "Provide legacy /dev/fb* device" - depends on FB + depends on FB_CORE default y help Say Y here if you want the legacy /dev/fb* device file and
@@ -75,7 +85,7 @@ config FB_DDC config FB_CFB_FILLRECT tristate - depends on FB + depends on FB_CORE help Include the cfb_fillrect function for generic software rectangle filling. This is used by drivers that don't provide their own
@@ -83,7 +93,7 @@ config FB_CFB_FILLRECT config FB_CFB_COPYAREA tristate - depends on FB + depends on FB_CORE help Include the cfb_copyarea function for generic software area copying. This is used by drivers that don't provide their own (accelerated)
@@ -91,7 +101,7 @@ config FB_CFB_COPYAREA config FB_CFB_IMAGEBLIT tristate - depends on FB + depends on FB_CORE help Include the cfb_imageblit function for generic software image blitting. This is used by drivers that don't provide their own
@@ -99,7 +109,7 @@ config FB_CFB_IMAGEBLIT config FB_CFB_REV_PIXELS_IN_BYTE bool - depends on FB + depends on FB_CORE help Allow generic frame-buffer functions to work on displays with 1, 2 and 4 bits per pixel depths which has opposite order of pixels in
@@ -107,7 +117,7 @@ config FB_CFB_REV_PIXELS_IN_BYTE config FB_SYS_FILLRECT tristate - depends on FB + depends on FB_CORE help Include the sys_fillrect function for generic software rectangle filling. This is used by drivers that don't provide their own
@@ -115,7 +125,7 @@ config FB_SYS_FILLRECT config FB_SYS_COPYAREA tristate - depends on FB + depends on FB_CORE help Include the sys_copyarea function for generic software area copying. This is used by drivers that don't provide their own (accelerated)
@@ -123,7 +133,7 @@ config FB_SYS_COPYAREA config FB_SYS_IMAGEBLIT tristate - depends on FB + depends on FB_CORE help Include the sys_imageblit function for generic software image blitting. This is used by drivers that don't provide their own
@@ -162,22 +172,22 @@ endchoice config FB_SYS_FOPS tristate - depends on FB + depends on FB_CORE config FB_DEFERRED_IO bool - depends on FB + depends on FB_CORE config FB_IO_HELPERS bool - depends on FB + depends on FB_CORE select FB_CFB_COPYAREA select FB_CFB_FILLRECT select FB_CFB_IMAGEBLIT config FB_SYS_HELPERS bool - depends on FB + depends on FB_CORE select FB_SYS_COPYAREA select FB_SYS_FILLRECT select FB_SYS_FOPS
@@ -185,7 +195,7 @@ config FB_SYS_HELPERS config FB_SYS_HELPERS_DEFERRED bool - depends on FB + depends on FB_CORE select FB_DEFERRED_IO select FB_SYS_HELPERS
diff --git a/drivers/video/fbdev/core/Makefile b/drivers/video/fbdev/core/Makefile
index 9150bafd9e89..2cd213716c12 100644
--- a/drivers/video/fbdev/core/Makefile
+++ b/drivers/video/fbdev/core/Makefile@@ -1,10 +1,10 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_FB_NOTIFY) += fb_notify.o -obj-$(CONFIG_FB) += fb.o -fb-y := fb_backlight.o \ - fb_info.o \ - fbmem.o fbmon.o fbcmap.o \ +obj-$(CONFIG_FB_CORE) += fb.o +fb-y := fb_info.o \ + fbmem.o fbcmap.o \ modedb.o fbcvt.o fb_cmdline.o fb_io_fops.o +fb-$(CONFIG_FB) += fb_backlight.o fbmon.o fb-$(CONFIG_FB_DEFERRED_IO) += fb_defio.o fb-$(CONFIG_FB_DEVICE) += fb_chrdev.o \ fb_procfs.o \
--
2.41.0