On Thu, Dec 19, 2019 at 09:03:42AM +0100, Marek Szyprowski wrote:
On 18.12.2019 17:24, Mark Brown wrote:
I've checked again the exact probe order and here is what happens in the system:
- first call to odroid_audio_probe() is just after:
[ 2.942428] samsung-i2s 3830000.i2s-sec: DMA channels sourced from device 3830000.i2s
- That time, i2s dai and max98090 devices are already registered.
However the snd_soc_of_get_dai_link_codecs() return -EPROBE_DEFER, because it cannot get the HDMI codec component.
- HDMI codec is being registered when Exynos DRM initializes. This
happens later:
[ 3.127833] [drm] Initialized exynos 1.1.0 20180330 for exynos-drm on minor 0
- Then odroid_audio_probe() is called again from the deferred probe
worker and succeeds:
[ 3.501198] ALSA device list: [ 3.501300] #0: Odroid-U3
- Then userspace starts:
[ 3.603825] Run /sbin/init as init process
- when userspace init scripts (alsactl) enumerates devices in the
system the lockdep warning is triggered:
[ 10.068990] ====================================================== [ 10.070970] WARNING: possible circular locking dependency detected [ 10.077136] 5.5.0-rc2-next-20191218 #7188 Not tainted [ 10.082168] ------------------------------------------------------ [ 10.088332] alsactl/1106 is trying to acquire lock:
- then alsa utils probably tries to load the saved values for the controls, what triggers the NULL ptr dereference:
[....] Setting up ALSA...[ 10.502672] 8<--- cut here --- [ 10.502772] Unable to handle kernel NULL pointer dereference at virtual address 000000b0
OK, so this is probably related to some of Morimoto-san's bisections. Is there any chance you coudld do a bisect to try to isolate where things go wrong?