UBSAN warning on unplugging USB4 DP alt mode from AMD Yellow Carp graphics card

[SRU Justification]

[Impact]

An UBSAN error is dumped once when unpluging a type-c cable (at DP Alt
Mode) from a AMD Yellow Carp equipped platform. No side effects found
so far, and subsequent hotplugs won't have this error again.

drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:6084:84
[ 38.099550] load of value 32 is not a valid value for type '_Bool'
[ 38.099552] CPU: 9 PID: 1451 Comm: Xorg Not tainted
5.15.0-2013-generic #13~20.04.1+pre14+lp1953008.1
[ 38.099554] Hardware name: AMD LilacKD-RMB/LilacKD-RMB, BIOS
RRL0080C 09/15/2021
[ 38.099555] Call Trace:
[ 38.099556] <TASK>
[ 38.099558] dump_stack_lvl+0x4a/0x5f
[ 38.099563] dump_stack+0x10/0x12
[ 38.099564] ubsan_epilogue+0x9/0x45
[ 38.099565] __ubsan_handle_load_invalid_value+0x70/0x80
[ 38.099568] create_stream_for_sink.cold+0x5d/0xbb [amdgpu]
...

[Fix]

Commit 63ad5371cd1e ("drm/amd/display: explicitly set is_dsc_supported
to false before use") in linux-next.

[Test Case]

1. Connect an external monitor via USB Type-C able to target platform
2. After external monitor turned on and screen was extended, unplug
   Type-C cable
3. check if a similar ubsan warning is dumpped to dmesg.

[Where problems could occur]

No. This initialize a variable before being referenced.

[Other Info]

While UBSAN is only turned on on 5.15 and newer, only Jammy is nominated
for this fix.

========== original bug report ==========

This is a follow-up for jammy 5.15 kernel backport of bug 1953008.

An UBSAN error is dumped once when unpluging a type-c cable (at DP Alt Mode). No side effects found so far, and subsequent hotplug won't have this error again.

[ 38.099545] ================================================================================
[ 38.099548] UBSAN: invalid-load in
/tmp/kernel-vicamo-28e409f5f0ef-xHcq/build/drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:6084:84
[ 38.099550] load of value 32 is not a valid value for type '_Bool'
[ 38.099552] CPU: 9 PID: 1451 Comm: Xorg Not tainted
5.15.0-2013-generic #13~20.04.1+pre14+lp1953008.1
[ 38.099554] Hardware name: AMD LilacKD-RMB/LilacKD-RMB, BIOS
RRL0080C 09/15/2021
[ 38.099555] Call Trace:
[ 38.099556] <TASK>
[ 38.099558] dump_stack_lvl+0x4a/0x5f
[ 38.099563] dump_stack+0x10/0x12
[ 38.099564] ubsan_epilogue+0x9/0x45
[ 38.099565] __ubsan_handle_load_invalid_value+0x70/0x80
[ 38.099568] create_stream_for_sink.cold+0x5d/0xbb [amdgpu]
[ 38.099707] ? dc_link_should_enable_fec+0x6a/0xa0 [amdgpu]
[ 38.099819] create_validate_stream_for_sink+0x59/0x150 [amdgpu]
[ 38.099918] dm_update_crtc_state+0x4f8/0x7a0 [amdgpu]
[ 38.100010] ? drm_atomic_get_private_obj_state+0x128/0x150 [drm]
[ 38.100024] amdgpu_dm_atomic_check+0x625/0xfb0 [amdgpu]
[ 38.100114] ? __ww_mutex_lock.isra.0+0x39/0x6d0
[ 38.100117] ? __cond_resched+0x19/0x30
[ 38.100118] ? __kmalloc_track_caller+0x1ab/0x4c0
[ 38.100121] ? amdgpu_dm_connector_atomic_duplicate_state+0x2c/0xf0 [amdgpu]
[ 38.100209] ? drm_mode_object_get+0x2a/0x60 [drm]
[ 38.100222] ?
__drm_atomic_helper_connector_duplicate_state+0x58/0x80
[drm_kms_helper]
[ 38.100231] drm_atomic_check_only+0x603/0x980 [drm]
[ 38.100243] drm_atomic_commit+0x18/0x50 [drm]
[ 38.100253] drm_atomic_connector_commit_dpms+0xdf/0x100 [drm]
[ 38.100264] drm_mode_obj_set_property_ioctl+0x1ae/0x420 [drm]
[ 38.100274] ? drm_mode_object_put.part.0+0x23/0x60 [drm]
[ 38.100284] ? drm_connector_set_obj_prop+0x90/0x90 [drm]
[ 38.100295] drm_connector_property_set_ioctl+0x3b/0x60 [drm]
[ 38.100305] drm_ioctl_kernel+0xae/0xf0 [drm]
[ 38.100315] drm_ioctl+0x271/0x490 [drm]
[ 38.100324] ? drm_connector_set_obj_prop+0x90/0x90 [drm]
[ 38.100334] ? do_epoll_ctl+0x255/0x640
[ 38.100337] amdgpu_drm_ioctl+0x4e/0x80 [amdgpu]
[ 38.100401] __x64_sys_ioctl+0x91/0xc0
[ 38.100403] do_syscall_64+0x5c/0xc0
[ 38.100404] ? syscall_exit_to_user_mode+0x27/0x50
[ 38.100406] ? do_syscall_64+0x69/0xc0
[ 38.100407] ? syscall_exit_to_user_mode+0x27/0x50
[ 38.100408] ? do_syscall_64+0x69/0xc0
[ 38.100409] ? syscall_exit_to_user_mode+0x27/0x50
[ 38.100410] ? do_syscall_64+0x69/0xc0
[ 38.100410] ? syscall_exit_to_user_mode+0x27/0x50
[ 38.100411] ? do_syscall_64+0x69/0xc0
[ 38.100412] ? asm_sysvec_apic_timer_interrupt+0xa/0x20
[ 38.100414] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 38.100415] RIP: 0033:0x7ff1c744050b
[ 38.100417] Code: 0f 1e fa 48 8b 05 85 39 0d 00 64 c7 00 26 00 00
00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00
00 0f 05 <48>
3d 01 f0 ff ff 73 01 c3 48 8b 0d 55 39 0d 00 f7 d8 64 89 01 48
[ 38.100419] RSP: 002b:00007ffe958832f8 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
[ 38.100421] RAX: ffffffffffffffda RBX: 00007ffe95883330 RCX: 00007ff1c744050b
[ 38.100421] RDX: 00007ffe95883330 RSI: 00000000c01064ab RDI: 000000000000000c
[ 38.100422] RBP: 00000000c01064ab R08: 0000000000000000 R09: 0000563365760270
[ 38.100422] R10: 0000000000000000 R11: 0000000000000246 R12: 00005633655bdf00
[ 38.100423] R13: 000000000000000c R14: 0000563365e674d0 R15: 0000000000000000
[ 38.100425] </TASK>
[ 38.100425] ================================================================================