Bugzilla – Bug 10898
Screen flashes during bootup
Last modified: 2019-01-25 10:35:25 UTC
R3945 During the boot sequence there are two brief color flashes on the screen. Usually blue, sometimes green. FWIW, the blue flash always fills the whole screen, while the green one seems to fill about 2/3.
r4402. There's just one flash now, just before the 'click' of bug 10716.
Ideally I'd like to address this for MP, but it's not a show stopper.
*** Bug 11470 has been marked as a duplicate of this bug. ***
*** Bug 11491 has been marked as a duplicate of this bug. ***
I've had a look at this and it appears that the flash is when the flash is when SDL starts and switches the framebuffer. The offending lines are: ipu_disable_channel(mxc_fbi->ipu_ch, true); ipu_uninit_channel(mxc_fbi->ipu_ch); in mxcfb.c. This disables the DMA that drives the lcd (later in the function it is re-enabled again). By removing this then the flash disappears, but it also makes the system unstable. I'll have to return to this again.
I should also add that you can see the blue flashes when switching virtual consoles using Ctl-Alt-Fx.
I'm re-targeting this for now. I don't fully understand the lcd driver code yet, and any changes here I think are too risky right now. I'll look at this again after we have upgraded to the 2.6.26 real-time kernel.
This appears much better now, but it should be looked at for 7.5.
Richard notes this has been improved, but it's a lot of work to fix it better. Seth to evaluate to see if it's good enough. Seth notes that it is a requirement for it not to flash, but will have a look.
moving current p2 bugs to p3 to make room for moving p1.5 bugs to p2
re-assigning Seth's bugs to Matt
Administrative move of 7.5 bugs. All P2, P3, P4 being downgraded one level. Will then split P1s.
Moving lower-priority bugs to next target
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