On Thursday, June 13, 2024 11:40:16 AM EDT Jocelyn Falempe wrote: > The race condition between fbcon and drm_panic can only occurs if > VT_CONSOLE is set. So update drm_panic dependency accordingly. > This will make it easier for Linux distributions to enable drm_panic > by disabling VT_CONSOLE, and keeping fbcon terminal. > The only drawback is that fbcon won't display the boot kmsg, so it > should rely on userspace to do that. > At least plymouth already handle this case with > https://gitlab.freedesktop.org/plymouth/plymouth/-/merge_requests/224 Hi An FYI, seeing this and https://fedoraproject.org/wiki/Changes/EnableDrmPanic , there is a slight issue with CONFIG_VT_CONSOLE=n in relation to systemd that was recently discovered outside of virt-manager VMs, (or computers that have no devices connected to the first serial port) This was seen on a full CONFIG_VT=n kernel, but it also happens on kernels with just CONFIG_VT_CONSOLE disabled. When /dev/console is /dev/ttyS0 (as that is the new default without the VT console, and /dev/ttyS0 is not connected to anything, isatty()'s TCGETS ioctl on /dev/console results in an input output error, causing isatty() to return false. Because of this, systemd's status logging then rejects /dev/console as not being a terminal device, and rejects writing status output to it, resulting in a decrease of verbosity available to Plymouth. It at first did not show up in my testing, because all my virt-manager and qemu VMs had serial devices attached, which would cause isatty() to return true on /dev/ttyS0 backed /dev/console, but now I have raised this with linux-serial. Thanks > > Suggested-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx> > --- > drivers/gpu/drm/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig > index a9df94291622..f5c989aed7e9 100644 > --- a/drivers/gpu/drm/Kconfig > +++ b/drivers/gpu/drm/Kconfig > @@ -107,7 +107,7 @@ config DRM_KMS_HELPER > > config DRM_PANIC > bool "Display a user-friendly message when a kernel panic occurs" > - depends on DRM && !FRAMEBUFFER_CONSOLE > + depends on DRM && !(FRAMEBUFFER_CONSOLE && VT_CONSOLE) > select DRM_KMS_HELPER > select FONT_SUPPORT > help > > base-commit: 2bae076f3e35234e42bd7c90acd8caae8368ba90 >
