Fix another oops reproducible when rebooting the board with the Adreno GPU wokring in the headless mode (e.g. iMX platforms). Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read [00000000] *pgd=74936831, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] ARM CPU: 0 PID: 51 Comm: reboot Not tainted 6.2.0-rc1-dirty #11 Hardware name: Freescale i.MX53 (Device Tree Support) PC is at msm_atomic_commit_tail+0x50/0x970 LR is at commit_tail+0x9c/0x188 pc : [<c06aa430>] lr : [<c067a214>] psr: 600e0013 sp : e0851d30 ip : ee4eb7eb fp : 00090acc r10: 00000058 r9 : c2193014 r8 : c4310000 r7 : c4759380 r6 : 07bef61d r5 : 00000000 r4 : 00000000 r3 : c44cc440 r2 : 00000000 r1 : 00000000 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 74910019 DAC: 00000051 Register r0 information: NULL pointer Register r1 information: NULL pointer Register r2 information: NULL pointer Register r3 information: slab kmalloc-1k start c44cc400 pointer offset 64 size 1024 Register r4 information: NULL pointer Register r5 information: NULL pointer Register r6 information: non-paged memory Register r7 information: slab kmalloc-128 start c4759380 pointer offset 0 size 128 Register r8 information: slab kmalloc-2k start c4310000 pointer offset 0 size 2048 Register r9 information: non-slab/vmalloc memory Register r10 information: non-paged memory Register r11 information: non-paged memory Register r12 information: non-paged memory Process reboot (pid: 51, stack limit = 0xc80046d9) Stack: (0xe0851d30 to 0xe0852000) 1d20: c4759380 fbd77200 000005ff 002b9c70 1d40: c4759380 c4759380 00000000 07bef61d 00000600 c0d6fe7c c2193014 00000058 1d60: 00090acc c067a214 00000000 c4759380 c4310000 00000000 c44cc854 c067a89c 1d80: 00000000 00000000 00000000 c4310468 00000000 c4759380 c4310000 c4310468 1da0: c4310470 c0643258 c4759380 00000000 00000000 c0c4ee24 00000000 c44cc810 1dc0: 00000000 c0c4ee24 00000000 c44cc810 00000000 0347d2a8 e0851e00 e0851e00 1de0: c4759380 c067ad20 c4310000 00000000 c44cc810 c27f8718 c44cc854 c067adb8 1e00: c4933000 00000002 00000001 00000000 00000000 c2130850 00000000 c2130854 1e20: c25fc488 00000000 c0ff162c 00000000 00000001 00000002 00000000 00000000 1e40: c43102c0 c43102c0 00000000 0347d2a8 c44cc810 c44cc814 c2133da8 c06d1a60 1e60: 00000000 00000000 00079028 c2012f24 fee1dead c4933000 00000058 c01431e4 1e80: 01234567 c0143a20 00000000 00000000 00000000 00000000 00000000 00000000 1ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1ec0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1ee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f80: 00000000 00000000 00000000 0347d2a8 00000002 00000004 00000078 00000058 1fa0: c010028c c0100060 00000002 00000004 fee1dead 28121969 01234567 00079028 1fc0: 00000002 00000004 00000078 00000058 0002fdc5 00000000 00000000 00090acc 1fe0: 00000058 becc9c64 b6e97e05 b6e0e5f6 600e0030 fee1dead 00000000 00000000 msm_atomic_commit_tail from commit_tail+0x9c/0x188 commit_tail from drm_atomic_helper_commit+0x160/0x188 drm_atomic_helper_commit from drm_atomic_commit+0xac/0xe0 drm_atomic_commit from drm_atomic_helper_disable_all+0x1b0/0x1c0 drm_atomic_helper_disable_all from drm_atomic_helper_shutdown+0x88/0x140 drm_atomic_helper_shutdown from device_shutdown+0x16c/0x240 device_shutdown from kernel_restart+0x38/0x90 kernel_restart from __do_sys_reboot+0x174/0x224 __do_sys_reboot from ret_fast_syscall+0x0/0x1c Exception stack(0xe0851fa8 to 0xe0851ff0) 1fa0: 00000002 00000004 fee1dead 28121969 01234567 00079028 1fc0: 00000002 00000004 00000078 00000058 0002fdc5 00000000 00000000 00090acc 1fe0: 00000058 becc9c64 b6e97e05 b6e0e5f6 Code: 15922088 1184421c e1500003 1afffff8 (e5953000) ---[ end trace 0000000000000000 ]--- Fixes: 0a58d2ae572a ("drm/msm: Make .remove and .shutdown HW shutdown consistent") Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> --- As can be seen from the backtrace, the error is generated because msm_atomic_commit_tail is called in the shutdown path. I've fixed the particular issue. Maybe we should consider shortcutting all mode_config initialization in case of headless Adreno chip? This would be more intrusive, so I haven't followed that path. However if you think that this should be a proper way to fix the issue, I'll try doing it. --- drivers/gpu/drm/msm/msm_atomic.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c index 1686fbb611fd..98c526246ff1 100644 --- a/drivers/gpu/drm/msm/msm_atomic.c +++ b/drivers/gpu/drm/msm/msm_atomic.c @@ -186,11 +186,16 @@ void msm_atomic_commit_tail(struct drm_atomic_state *state) struct msm_kms *kms = priv->kms; struct drm_crtc *async_crtc = NULL; unsigned crtc_mask = get_crtc_mask(state); - bool async = kms->funcs->vsync_time && - can_do_async(state, &async_crtc); + bool async; + + if (!kms) + return; trace_msm_atomic_commit_tail_start(async, crtc_mask); + async = kms->funcs->vsync_time && + can_do_async(state, &async_crtc); + kms->funcs->enable_commit(kms); /* -- 2.39.0