[v2,1/2] fbdev: Split frame buffer support in FB and FB_CORE symbols
Commit Message
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).
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---
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 | 2 +-
5 files changed, 29 insertions(+), 19 deletions(-)
Comments
Hi,
Does this series apply on top of the previous series or on what?
On 7/1/23 14:44, Javier Martinez Canillas wrote:
> 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).
>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> ---
>
> 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 | 2 +-
> 5 files changed, 29 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
> index cecf15418632..da6f7d588f17 100644
> --- a/drivers/video/fbdev/Kconfig
> +++ b/drivers/video/fbdev/Kconfig
> @@ -6,8 +6,12 @@
> config FB_NOTIFY
> bool
>
> +menuconfig FB_CORE
> + tristate "Core support for frame buffer devices"
> +
I could be reading this incorrectly, but FB_CORE does not appear to
be a non-visible Kconfig symbol here.
> 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
thanks.
On Sat, Jul 1, 2023, at 23:44, Javier Martinez Canillas wrote:
> 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).
>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> ---
I found two more things now:
>
> +menuconfig FB_CORE
> + tristate "Core support for frame buffer devices"
> +
This is not actually a hidden option, since you left the prompt
after the 'tristate' keyword. There is also no pointn in having
it as a menu, just use the simpler
config FB_CORE
tristate
or (as in my other email)
config FB_CORE
def_tristate FB || (DRM && DRM_FBDEV_EMULATION)
> @@ -44,7 +54,7 @@ menuconfig FB
>
> config FIRMWARE_EDID
> bool "Enable firmware EDID"
> - depends on FB
> + depends on FB_CORE
> help
> This enables access to the EDID transferred from the firmware.
> On the i386, this is from the Video BIOS. Enable this if DDC/I2C
> @@ -59,7 +69,7 @@ config FIRMWARE_EDID
>
> config FB_DEVICE
> bool "Provide legacy /dev/fb* device"
> - depends on FB
> + select FB_CORE
> default y
> help
> Say Y here if you want the legacy /dev/fb* device file and
These are now the only user visible sub-options when CONFIG_FB is
disabled. I missed FIRMWARE_EDID earlier, but this also looks like
it can clearly be left as depending on FB since nothing else calls
fb_firmware_edid. In fact, it looks like all of fbmon.c could be
left out since none of its exported symbols are needed for DRM.
That would leave CONFIG_FB_DEVICE as the only user visible option
for DRM-only configs, which is slightly odd for the menuconfig,
so I still wonder if that could be done differently.
Is there actually a point in configurations for kernels with FB=y,
DRM=n and FB_DEVICE=n? If we don't expect that to be a useful
configuration, an easier way would be to have CONFIG_FB turn it
on implicitly and instead have a user-visible Kconfig option
below CONFIG_DRM_FBDEV_EMULATION that allows controlling the
creation of /dev/fb*.
Arnd
Hi Arnd,
On Sun, Jul 2, 2023 at 12:25 AM Arnd Bergmann <arnd@arndb.de> wrote:
> On Sat, Jul 1, 2023, at 23:44, Javier Martinez Canillas wrote:
> > 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).
> >
> > Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> > @@ -59,7 +69,7 @@ config FIRMWARE_EDID
> >
> > config FB_DEVICE
> > bool "Provide legacy /dev/fb* device"
> > - depends on FB
> > + select FB_CORE
> > default y
> > help
> > Say Y here if you want the legacy /dev/fb* device file and
>
> These are now the only user visible sub-options when CONFIG_FB is
> disabled. I missed FIRMWARE_EDID earlier, but this also looks like
> it can clearly be left as depending on FB since nothing else calls
> fb_firmware_edid. In fact, it looks like all of fbmon.c could be
> left out since none of its exported symbols are needed for DRM.
>
> That would leave CONFIG_FB_DEVICE as the only user visible option
> for DRM-only configs, which is slightly odd for the menuconfig,
> so I still wonder if that could be done differently.
>
> Is there actually a point in configurations for kernels with FB=y,
> DRM=n and FB_DEVICE=n? If we don't expect that to be a useful
> configuration, an easier way would be to have CONFIG_FB turn it
> on implicitly and instead have a user-visible Kconfig option
> below CONFIG_DRM_FBDEV_EMULATION that allows controlling the
> creation of /dev/fb*.
Such a combination would allow the user to still have a text console
on a legacy fbdev, while not having to worry about possible security
ramifications of providing fbdev userspace access.
Gr{oetje,eeting}s,
Geert
Geert Uytterhoeven <geert@linux-m68k.org> writes:
> Hi Arnd,
>
[...]
>>
>> That would leave CONFIG_FB_DEVICE as the only user visible option
>> for DRM-only configs, which is slightly odd for the menuconfig,
>> so I still wonder if that could be done differently.
>>
>> Is there actually a point in configurations for kernels with FB=y,
>> DRM=n and FB_DEVICE=n? If we don't expect that to be a useful
>> configuration, an easier way would be to have CONFIG_FB turn it
>> on implicitly and instead have a user-visible Kconfig option
>> below CONFIG_DRM_FBDEV_EMULATION that allows controlling the
>> creation of /dev/fb*.
>
> Such a combination would allow the user to still have a text console
> on a legacy fbdev, while not having to worry about possible security
> ramifications of providing fbdev userspace access.
>
Exactly, it may be a possible combination. Not sure how useful what would
be in practice but we shouldn't restrict that IMO.
Hi
Am 01.07.23 um 23:44 schrieb Javier Martinez Canillas:
> 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).
>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> ---
>
> 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 | 2 +-
> 5 files changed, 29 insertions(+), 19 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..da6f7d588f17 100644
> --- a/drivers/video/fbdev/Kconfig
> +++ b/drivers/video/fbdev/Kconfig
> @@ -6,8 +6,12 @@
> config FB_NOTIFY
> bool
>
> +menuconfig FB_CORE
> + tristate "Core support for frame buffer devices"
With the text, this is visible; as others noted.
> +
> menuconfig FB
> - tristate "Support for frame buffer devices"
> + tristate "Support for frame buffer device drivers"
Just keep the text as-is.
> + select FB_CORE
> select FB_NOTIFY
> select VIDEO_CMDLINE
> help
> @@ -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.
>
> @@ -44,7 +54,7 @@ menuconfig FB
>
> config FIRMWARE_EDID
> bool "Enable firmware EDID"
> - depends on FB
> + depends on FB_CORE
> help
> This enables access to the EDID transferred from the firmware.
> On the i386, this is from the Video BIOS. Enable this if DDC/I2C
> @@ -59,7 +69,7 @@ config FIRMWARE_EDID
>
> config FB_DEVICE
> bool "Provide legacy /dev/fb* device"
> - depends on FB
> + select FB_CORE
This should depend on FB_CORE.
Best regards
Thomas
> 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..4c2e4a026d12 100644
> --- a/drivers/video/fbdev/core/Makefile
> +++ b/drivers/video/fbdev/core/Makefile
> @@ -1,6 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_FB_NOTIFY) += fb_notify.o
> -obj-$(CONFIG_FB) += fb.o
> +obj-$(CONFIG_FB_CORE) += fb.o
> fb-y := fb_backlight.o \
> fb_info.o \
> fbmem.o fbmon.o fbcmap.o \
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
Thomas Zimmermann <tzimmermann@suse.de> writes:
Hello Thomas,
Thanks for your review.
> Hi
>
> Am 01.07.23 um 23:44 schrieb Javier Martinez Canillas:
[...]
>>
>> +menuconfig FB_CORE
>> + tristate "Core support for frame buffer devices"
>
> With the text, this is visible; as others noted.
>
Yes, I misremembered what made a Kconfig symbol non-visible, and thought
that was just the lack of a help section but forgot to remove the prompt.
This is already fixed in v3.
>> +
>> menuconfig FB
>> - tristate "Support for frame buffer devices"
>> + tristate "Support for frame buffer device drivers"
>
> Just keep the text as-is.
>
I disagree. Because we are slightly changing the Kconfig symbol semantics
here, for instance CONFIG_FB_CORE + CONFIG_DRM_FBDEV_EMULATION will also
provide a frame buffer device (and with CONFIG_FB_DEVICE, will be exposed
to user-space as a /dev/fb? device).
So now CONFIG_FB is really about allowing the native fbdev drivers to be
enabled. That's why I'm changing the prompt text to make that more clear.
[...]
>> config FB_DEVICE
>> bool "Provide legacy /dev/fb* device"
>> - depends on FB
>> + select FB_CORE
>
> This should depend on FB_CORE.
>
Yes, already fixed in v3 too. I did a select to prevent symbol circular
dependencies but doing that lead to CONFIG_FB_CORE=y even if CONFIG_DRM
was set as a module.
But with the "select FB_CORE if DRM_FBDEV_EMULATION" in the DRM symbol as
Arnd suggested, I was able to have FB_DEVICE to depend on FB_CORE again.
> Best regards
> Thomas
>
Hi
Am 03.07.23 um 09:46 schrieb Javier Martinez Canillas:
> Thomas Zimmermann <tzimmermann@suse.de> writes:
>
> Hello Thomas,
>
> Thanks for your review.
>
>> Hi
>>
>> Am 01.07.23 um 23:44 schrieb Javier Martinez Canillas:
>
> [...]
>
>>>
>>> +menuconfig FB_CORE
>>> + tristate "Core support for frame buffer devices"
>>
>> With the text, this is visible; as others noted.
>>
>
> Yes, I misremembered what made a Kconfig symbol non-visible, and thought
> that was just the lack of a help section but forgot to remove the prompt.
>
> This is already fixed in v3.
>
>>> +
>>> menuconfig FB
>>> - tristate "Support for frame buffer devices"
>>> + tristate "Support for frame buffer device drivers"
>>
>> Just keep the text as-is.
>>
>
> I disagree. Because we are slightly changing the Kconfig symbol semantics
> here, for instance CONFIG_FB_CORE + CONFIG_DRM_FBDEV_EMULATION will also
> provide a frame buffer device (and with CONFIG_FB_DEVICE, will be exposed
> to user-space as a /dev/fb? device).
>
> So now CONFIG_FB is really about allowing the native fbdev drivers to be
> enabled. That's why I'm changing the prompt text to make that more clear.
>
> [...]
>
>>> config FB_DEVICE
>>> bool "Provide legacy /dev/fb* device"
>>> - depends on FB
>>> + select FB_CORE
>>
>> This should depend on FB_CORE.
>>
>
> Yes, already fixed in v3 too. I did a select to prevent symbol circular
> dependencies but doing that lead to CONFIG_FB_CORE=y even if CONFIG_DRM
> was set as a module.
>
> But with the "select FB_CORE if DRM_FBDEV_EMULATION" in the DRM symbol as
> Arnd suggested, I was able to have FB_DEVICE to depend on FB_CORE again.
BTW, where does this item now show up in the menu? It used to be in the
framebuffer menu. It's now in the graphics-drivers menu?
Best regards
Thomas
>
>> Best regards
>> Thomas
>>
>
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
Thomas Zimmermann <tzimmermann@suse.de> writes:
[...]
>>>> config FB_DEVICE
>>>> bool "Provide legacy /dev/fb* device"
>>>> - depends on FB
>>>> + select FB_CORE
>>>
>>> This should depend on FB_CORE.
>>>
>>
>> Yes, already fixed in v3 too. I did a select to prevent symbol circular
>> dependencies but doing that lead to CONFIG_FB_CORE=y even if CONFIG_DRM
>> was set as a module.
>>
>> But with the "select FB_CORE if DRM_FBDEV_EMULATION" in the DRM symbol as
>> Arnd suggested, I was able to have FB_DEVICE to depend on FB_CORE again.
>
> BTW, where does this item now show up in the menu? It used to be in the
> framebuffer menu. It's now in the graphics-drivers menu?
>
No, it's still in the framebuffer menu. But after the FB_CORE split the
menuconfig ends broken (no sub-level for fbdev drivers anymore).
I was talking with Arnd and Geert about this. I think that will pause this
series and instead first focus on cleaning up the fbdev Kconfig, then it
should be easier to add the FB_CORE on top of that.
> Best regards
> Thomas
>
@@ -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-$(CONFIG_FB_CORE) += arch/x86/video/
####
# boot loader support. Several targets are kept for legacy purposes
@@ -1,2 +1,2 @@
# SPDX-License-Identifier: GPL-2.0-only
-obj-$(CONFIG_FB) += fbdev.o
+obj-$(CONFIG_FB_CORE) += fbdev.o
@@ -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
@@ -6,8 +6,12 @@
config FB_NOTIFY
bool
+menuconfig FB_CORE
+ tristate "Core support for frame buffer devices"
+
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
@@ -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.
@@ -44,7 +54,7 @@ menuconfig FB
config FIRMWARE_EDID
bool "Enable firmware EDID"
- depends on FB
+ depends on FB_CORE
help
This enables access to the EDID transferred from the firmware.
On the i386, this is from the Video BIOS. Enable this if DDC/I2C
@@ -59,7 +69,7 @@ config FIRMWARE_EDID
config FB_DEVICE
bool "Provide legacy /dev/fb* device"
- depends on FB
+ select 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
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_FB_NOTIFY) += fb_notify.o
-obj-$(CONFIG_FB) += fb.o
+obj-$(CONFIG_FB_CORE) += fb.o
fb-y := fb_backlight.o \
fb_info.o \
fbmem.o fbmon.o fbcmap.o \