4.6-rc2: regression with omap video and lockdep (was Re: 4.4, 4.6: camera and unlock buttons produce tons of interrupts (was Re: N900 sleep mode))

Pavel Machek
2016-04-11T08:27:49Z

Hi!

> > > Nothing idling for me with your .config.. And it seems slower to boot
> > > compared to omap2plus_defconfig? Maybe because of the extra GPIO
> > > interrupts?
> >
> > Extra interrupts only happen when enable_off_mode is 1, so that should
> > not be an issue during boot.
>
> OK maybe it's just the extra driver probe time then.

Heh. I had earlyprintk enabled. That should explain it.

> Well I've been just using omap2plus_defconfig with:
>
> # modprobe tsc2005
> # modprobe gpio_backlight
> # modprobe panel_sony_acx565akm
> # modprobe omapfb
>
> # echo 255 > /sys/class/backlight/acx565akm/brightness
>
> And then the following to blank for idle:
>
> # echo 1 > /sys/devices/platform/omapfb/graphics/fb0/blank
>
> But in the world of eternal regressions, I'm not seeing anything
> on the framebuffer with v4.6-rc2 :( No idea what broke it or when
> as my n900 is in the rack.

Can you try this patch to your config -- disabling lockdep? It should
fix the video for you. (And if you have the serial console... do you
see any warnings from lockdep?)

Thanks,
Pavel

--- config.def 2016-04-08 21:50:04.519622137 +0200
+++ .config 2016-04-11 10:22:52.988193318 +0200
@@ -4183,15 +4183,12 @@
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_MUTEXES=y
# CONFIG_DEBUG_WW_MUTEX_SLOWPATH is not set
-CONFIG_DEBUG_LOCK_ALLOC=y
-CONFIG_PROVE_LOCKING=y
-CONFIG_LOCKDEP=y
+# CONFIG_DEBUG_LOCK_ALLOC is not set
+# CONFIG_PROVE_LOCKING is not set
# CONFIG_LOCK_STAT is not set
-# CONFIG_DEBUG_LOCKDEP is not set
# CONFIG_DEBUG_ATOMIC_SLEEP is not set
# CONFIG_DEBUG_LOCKING_API_SELFTESTS is not set
# CONFIG_LOCK_TORTURE_TEST is not set
-CONFIG_TRACE_IRQFLAGS=y
CONFIG_STACKTRACE=y
# CONFIG_DEBUG_KOBJECT is not set
# CONFIG_DEBUG_BUGVERBOSE is not set
@@ -4204,8 +4201,7 @@
#
# RCU Debugging
#
-CONFIG_PROVE_RCU=y
-# CONFIG_PROVE_RCU_REPEATEDLY is not set
+# CONFIG_PROVE_RCU is not set
# CONFIG_SPARSE_RCU_POINTER is not set
# CONFIG_TORTURE_TEST is not set
# CONFIG_RCU_TORTURE_TEST is not set