[REGRESSION] NULL pointer dereference when waking up monitor

Submitted by mr...@..il.com

Assigned to Default DRI bug account

Link to original bug (#107300)

Description

Created attachment 140719
dmesg

I'm noticing this with linux-17.6 on an RX 480, but did not experience this problem with linux-4.16 and earlier.

I let the machine without any input for a while, and it automatically puts the monitor to sleep. To wake up the screen, I move the mouse or hit the keyboard.

About a third of the time, the login screen comes up, and there's no response. SSH then dmesg points to an amazingly well crafted NULL pointer dereference in [amdgpu].

Surprisingly, this isn't some 4billionk triple-gazillion monitor setup, which I've always had driver issues with. This issue happens with a single display.

For fast access, this is the backtrace:
[59233.951991] Call Trace:
[59233.952068] dm_update_crtcs_state+0x26c/0x4d0 [amdgpu]
[59233.952140] amdgpu_dm_atomic_check+0x1b1/0x3b0 [amdgpu]
[59233.952172] drm_atomic_check_only+0x360/0x4f0 [drm]
[59233.952192] drm_atomic_commit+0x13/0x50 [drm]
[59233.952211] drm_atomic_connector_commit_dpms+0xdb/0x100 [drm]
[59233.952230] drm_mode_obj_set_property_ioctl+0x178/0x280 [drm]
[59233.952249] ? drm_mode_connector_set_obj_prop+0x80/0x80 [drm]
[59233.952266] drm_mode_connector_property_set_ioctl+0x39/0x60 [drm]
[59233.952283] drm_ioctl_kernel+0x5b/0xb0 [drm]
[59233.952300] drm_ioctl+0x1b3/0x370 [drm]
[59233.952318] ? drm_mode_connector_set_obj_prop+0x80/0x80 [drm]
[59233.952375] amdgpu_drm_ioctl+0x49/0x80 [amdgpu]
[59233.952382] do_vfs_ioctl+0xa4/0x610
[59233.952386] ksys_ioctl+0x60/0x90
[59233.952389] __x64_sys_ioctl+0x16/0x20
[59233.952394] do_syscall_64+0x5b/0x160
[59233.952399] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Attachment 140719, "dmesg":
file_107300.txt