On Wed, Jan 4, 2023 at 10:09 AM Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
>
>
>
> On 1/3/2023 7:51 AM, Dmitry Baryshkov wrote:
> > Fix another oops reproducible when rebooting the board with the Adreno
> > GPU wokring in the headless mode (e.g. iMX platforms).
> wokring ---> working
> >
> > 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")
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
>
> How is this null pointer hitting?
>
> priv->kms is assigned in the msm_drm_init() which happens in the bind.
I think we want to solve this higher up.. hitting atomic commit path
on a device which has no kms resources (planes, CRTCs, etc) seems
pretty wrong
BR,
-R
> Only then we register the dri card for the commit which means commit
> cannot come before that.
>
> So, how can this sequence be possible?
>
> > ---
> >
> > Changes since v1:
> > - Moved setting of `async' before the call to trace to fix the
> > uninitialized variable warning
> >
> > ---
> > drivers/gpu/drm/msm/msm_atomic.c | 7 ++++++-
> > 1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
> > index 1686fbb611fd..d8cded52cabf 100644
> > --- a/drivers/gpu/drm/msm/msm_atomic.c
> > +++ b/drivers/gpu/drm/msm/msm_atomic.c
> > @@ -186,7 +186,12 @@ 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 &&
> > + bool async;
> > +
> > + if (!kms)
> > + return;
> > +
> > + async = kms->funcs->vsync_time &&
> > can_do_async(state, &async_crtc);
> >
> > trace_msm_atomic_commit_tail_start(async, crtc_mask);
