Hi Mark, On 19.12.2019 13:37, Mark Brown wrote: > 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: >> >> 1. first call to odroid_audio_probe() is just after: >> >> [ 2.942428] samsung-i2s 3830000.i2s-sec: DMA channels sourced from device 3830000.i2s >> >> 2. 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. >> >> 3. 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 >> >> 4. Then odroid_audio_probe() is called again from the deferred probe >> worker and succeeds: >> >> [ 3.501198] ALSA device list: >> [ 3.501300] #0: Odroid-U3 >> 5. Then userspace starts: >> [ 3.603825] Run /sbin/init as init process >> >> 6. 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: >> >> 7. 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? I can do the bisect, but please let me know exactly what to bisect. The initial bisection I did was from v5.5-rc1 to linux-next and pointed to the $subject commit. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
