Re: Adding deferred fbcon console takeover to the Fedora kernels

Hi All, On 28-06-18 16:19, Hans de Goede wrote: > Hi All, > > Good news on the patch to make the loglevel for quiet configurable, > this has been accepted into -next now. I plan to add this to the > Fedora kernels soonish and set the quiet loglevel to 3 as > discussed earlier. > > Today another related patch-set got merged, see the last 3 > commits here: > https://github.com/bzolnier/linux/commits/ib-fbdev-drm-v4.19-deferred-con... > > I would also like to add these 3 patches to the Fedora 4.18 > kernel (for F29+). > > The end goal here is a boot where the firmware shows its boot graphics > and these stay in place for a couple of seconds until the GUI loads and > the GUI then smoothly takes over the framebuffer without any disruptions. > > See here for an example of what this looks like on my main workstation: > > https://fedorapeople.org/~jwrdegoede/flickerfree-videos/workstation-norma... > > Shim has already been modified to leave the framebuffer as setup by > the firmware intact and patches for grub have been merged, but not > yet build for F29+. > > Combined with the hidden grub menu feature for F29: > > https://fedoraproject.org/wiki/Changes/HiddenGrubMenu > > This means that the framebuffer is still showing the boot graphics > (e.g. vendor logo) when the kernel loads. > > Without the "deferred fbcon console takeover" patches the fbcon > will takeover from dummycon as the console driver as soon as > the efifb registers itself as a fbdev, clearing the screen to > black. breaking the desired boot experience. > > The deferred console takeover patches make the fbcon code delay > taking over as the console until the first character is output > on the console. > > I've tested this code with the following scenarios: > > 1) Remove quiet from the kernel commandline -> fbcon binds right away > because messages are logged to the dummycon before efifb loads > > 2) Mess up the root= kernel argument -> As soon as dracut prints > its timeout message for finding the rootfs, fbcon binds and shows > the timeout message > > 3) Detailed view in plymouth mode (press ESC to show boot msg) -> > plymouth retains drm master rights on /dev/dri/card? while it > tries to show the details. The blocks fbcon accessing the fbdev > device registered by the kms driver, so nothing will be shown > until plymouth exits (and releases the drm-master rights). > > This really is a plymouth bug, I've submitted plymouth patches > fixing this here: > https://bugs.freedesktop.org/show_bug.cgi?id=107047 I got an ack from Ray for these patches and for adding these patches to the Fedora plymouth package as downstream patches (until the next upstream release). A new plymouth package fixing this is building now: https://koji.fedoraproject.org/koji/buildinfo?buildID=1102343