RE: [PATCH] drm/amdgpu/pm: fix the null pointer while the smu is disabled

["Liu, Aaron" <Aaron.Liu@amd.com>]

[AMD Official Use Only]

Reviewed-by: Aaron Liu <aaron.liu@amd.com>

> -----Original Message-----
> From: amd-gfx <amd-gfx-bounces@lists.freedesktop.org> On Behalf Of
> Huang Rui
> Sent: Friday, April 15, 2022 12:13 PM
> To: amd-gfx@lists.freedesktop.org
> Cc: Deucher, Alexander <Alexander.Deucher@amd.com>; Huang, Tim
> <Tim.Huang@amd.com>; Quan, Evan <Evan.Quan@amd.com>; Huang, Ray
> <Ray.Huang@amd.com>; Du, Xiaojian <Xiaojian.Du@amd.com>
> Subject: [PATCH] drm/amdgpu/pm: fix the null pointer while the smu is
> disabled
> 
> It needs to check if the pp_funcs is initialized while release the context,
> otherwise it will trigger null pointer panic while the software smu is not
> enabled.
> 
> [ 1109.404555] BUG: kernel NULL pointer dereference, address:
> 0000000000000078 [ 1109.404609] #PF: supervisor read access in kernel mode
> [ 1109.404638] #PF: error_code(0x0000) - not-present page [ 1109.404657]
> PGD 0 P4D 0 [ 1109.404672] Oops: 0000 [#1] PREEMPT SMP NOPTI
> [ 1109.404701] CPU: 7 PID: 9150 Comm: amdgpu_test Tainted: G           OEL
> 5.16.0-custom #1
> [ 1109.404732] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS
> VirtualBox 12/01/2006 [ 1109.404765] RIP:
> 0010:amdgpu_dpm_force_performance_level+0x1d/0x170 [amdgpu]
> [ 1109.405109] Code: 5d c3 44 8b a3 f0 80 00 00 eb e5 66 90 0f 1f 44 00 00 55 48
> 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 08 4c 8b b7 f0 7d 00 00 <49> 83 7e 78
> 00 0f 84 f2 00 00 00 80 bf 87 80 00 00 00 48 89 fb 0f [ 1109.405176] RSP:
> 0018:ffffaf3083ad7c20 EFLAGS: 00010282 [ 1109.405203] RAX:
> 0000000000000000 RBX: ffff9796b1c14600 RCX: 0000000002862007
> [ 1109.405229] RDX: ffff97968591c8c0 RSI: 0000000000000001 RDI:
> ffff9796a3700000 [ 1109.405260] RBP: ffffaf3083ad7c50 R08: ffffffff9897de00
> R09: ffff979688d9db60 [ 1109.405286] R10: 0000000000000000 R11:
> ffff979688d9db90 R12: 0000000000000001 [ 1109.405316] R13:
> ffff9796a3700000 R14: 0000000000000000 R15: ffff9796a3708fc0 [ 1109.405345]
> FS:  00007ff055cff180(0000) GS:ffff9796bfdc0000(0000)
> knlGS:0000000000000000 [ 1109.405378] CS:  0010 DS: 0000 ES: 0000 CR0:
> 0000000080050033 [ 1109.405400] CR2: 0000000000000078 CR3:
> 000000000a394000 CR4: 00000000000506e0 [ 1109.405434] Call Trace:
> [ 1109.405445]  <TASK>
> [ 1109.405456]  ? delete_object_full+0x1d/0x20 [ 1109.405480]
> amdgpu_ctx_set_stable_pstate+0x7c/0xa0 [amdgpu] [ 1109.405698]
> amdgpu_ctx_fini.part.0+0xcb/0x100 [amdgpu] [ 1109.405911]
> amdgpu_ctx_do_release+0x71/0x80 [amdgpu] [ 1109.406121]
> amdgpu_ctx_ioctl+0x52d/0x550 [amdgpu] [ 1109.406327]  ?
> _raw_spin_unlock+0x1a/0x30 [ 1109.406354]  ?
> drm_gem_handle_delete+0x81/0xb0 [drm] [ 1109.406400]  ?
> amdgpu_ctx_get_entity+0x2c0/0x2c0 [amdgpu] [ 1109.406609]
> drm_ioctl_kernel+0xb6/0x140 [drm]
> 
> Signed-off-by: Huang Rui <ray.huang@amd.com>
> ---
>  drivers/gpu/drm/amd/pm/amdgpu_dpm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> index 1d63f1e8884c..428623e64e8f 100644
> --- a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> +++ b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> @@ -717,7 +717,7 @@ int amdgpu_dpm_force_performance_level(struct
> amdgpu_device *adev,
> 
> 	AMD_DPM_FORCED_LEVEL_PROFILE_MIN_MCLK |
> 
> 	AMD_DPM_FORCED_LEVEL_PROFILE_PEAK;
> 
> -	if (!pp_funcs->force_performance_level)
> +	if (!pp_funcs || !pp_funcs->force_performance_level)
>  		return 0;
> 
>  	if (adev->pm.dpm.thermal_active)
> --
> 2.25.1