Comment # 4 on bug 1137067 from Ross Green

Looking at both these stack traces it appears that these systems are
caught somewhere within the KMS as drm_kms_helper is caught in the stack call
unwind.
Seems like the nouveau_connector_detect area is involved.

Might be worth looking at drm_nouveau changes in this area between the kernel
releases.

Thanks Felix for verifying the above condition on different hardware,
all be it with a NVIDIA display adapter.

On the whole the nouveau driver seems much less stable in Leap 15.1 compared to
Leap 15.0. Often get lookups in 15.1 where the display just completely freezes
and can't even get back to a virtual terminal to investigate.

Ross

Jun 02 15:17:24 p5bse kernel:  ? drm_dp_dpcd_access+0x69/0xf0 [drm_kms_helper]
Jun 02 15:17:24 p5bse kernel:  ? drm_dp_dpcd_read+0x2e/0xc0 [drm_kms_helper]
Jun 02 15:17:24 p5bse kernel:  ? drm_dp_cec_set_edid+0x4e/0x140
[drm_kms_helper]
Jun 02 15:17:24 p5bse kernel:  ? nouveau_connector_detect+0x1fd/0x440 [nouveau]
Jun 02 15:17:24 p5bse kernel:  ?
drm_helper_probe_single_connector_modes+0xc3/0x6b0 [drm_kms_helper]
Jun 02 15:17:24 p5bse kernel:  ? nouveau_connector_force+0x80/0x80 [nouveau]
Jun 02 15:17:24 p5bse kernel:  ?
drm_helper_probe_single_connector_modes+0xc3/0x6b0 [drm_kms_helper]
Jun 02 15:17:24 p5bse kernel:  ? dev_vprintk_emit+0x108/0x220
Jun 02 15:17:24 p5bse kernel:  ? drm_setup_crtcs+0x139/0xa80 [drm_kms_helper]
Jun 02 15:17:24 p5bse kernel:  ?
__drm_fb_helper_initial_config_and_unlock+0x2d/0x400 [drm_kms_helper]
Jun 02 15:17:24 p5bse kernel:  ? mutex_lock+0xe/0x30
Jun 02 15:17:24 p5bse kernel:  ? nouveau_fbcon_init+0x14f/0x1c0 [nouveau]