diff options
| author | Hans de Goede <hdegoede@redhat.com> | 2018-06-28 15:20:30 +0200 |
|---|---|---|
| committer | Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> | 2018-06-28 15:20:30 +0200 |
| commit | 83d83bebf40132e2d55ec58af666713cc76f9764 (patch) | |
| tree | 8539ca6adfd8778e9c73111e23770adc7b04beb2 /drivers/video/console/Kconfig | |
| parent | 3bd3a0e330aae4fffa8028aba2407ef615ab040b (diff) | |
| download | lwn-83d83bebf40132e2d55ec58af666713cc76f9764.tar.gz lwn-83d83bebf40132e2d55ec58af666713cc76f9764.zip | |
console/fbcon: Add support for deferred console takeover
Currently fbcon claims fbdevs as soon as they are registered and takes over
the console as soon as the first fbdev gets registered.
This behavior is undesirable in cases where a smooth graphical bootup is
desired, in such cases we typically want the contents of the framebuffer
(typically a vendor logo) to stay in place as is.
The current solution for this problem (on embedded systems) is to not
enable fbcon.
This commit adds a new FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER config option,
which when enabled defers fbcon taking over the console from the dummy
console until the first text is displayed on the console. Together with the
"quiet" kernel commandline option, this allows fbcon to still be used
together with a smooth graphical bootup, having it take over the console as
soon as e.g. an error message is logged.
Note the choice to detect the first console output in the dummycon driver,
rather then handling this entirely inside the fbcon code, was made after
2 failed attempts to handle this entirely inside the fbcon code. The fbcon
code is woven quite tightly into the console code, making this to only
feasible option.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Diffstat (limited to 'drivers/video/console/Kconfig')
| -rw-r--r-- | drivers/video/console/Kconfig | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig index 4110ba7d7ca9..e91edef98633 100644 --- a/drivers/video/console/Kconfig +++ b/drivers/video/console/Kconfig @@ -150,6 +150,17 @@ config FRAMEBUFFER_CONSOLE_ROTATION such that other users of the framebuffer will remain normally oriented. +config FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER + bool "Framebuffer Console Deferred Takeover" + depends on FRAMEBUFFER_CONSOLE=y && DUMMY_CONSOLE=y + help + If enabled this defers the framebuffer console taking over the + console from the dummy console until the first text is displayed on + the console. This is useful in combination with the "quiet" kernel + commandline option to keep the framebuffer contents initially put up + by the firmware in place, rather then replacing the contents with a + black screen as soon as fbcon loads. + config STI_CONSOLE bool "STI text console" depends on PARISC && HAS_IOMEM |