i.MX6 Sabre SDP video does not always start

[wayne_s]

I am running the 13.04.24 version of ltib (Linux version 3.0.35-2508-g54750ff), and video usually starts up during boot (I get 4 penguins while the kernel is booting, and the matchbox desktop comes up). 

Every now and then, I get no display on the LCD but the system seems to run fine otherwise.  Unblanking the display with:

    echo 0 >/sys/class/graphics/fb0/blank

    cat /etc/splash.bmp >/dev/fb0

    echo -e -n "\33[9;0]\33[14;0]" >/dev/console

does not do anything, so I don't believe it to be in the screen blanking subsystem.

Does anyone have suggestions on how to debug this problem?  It is an intermittent problem that happens with either resets or power cycling.  There are no differences in the dmesg output between a successful reboot with graphics and one without.

.

Thanks,

Wayne

Original Attachment has been moved to: boot_no_display.txt.zip

[FranciscoCarril]

Your issue is very hard to reproduce.

Have you tried with a different screen (hdmi for example) 

is it the same behavior?

[wayne_s · Accepted solution]

This hasn't happened again since I switched to Yocto BSP and included 'ldb=dul0' on the kernel boot parameters line.