[Intel-xe] ✓ CI.checkpatch: success for drm/xe: fix mem_access for early lrc generation (rev2)

[Patchwork]

== Series Details ==

Series: drm/xe: fix mem_access for early lrc generation (rev2)
URL   : https://patchwork.freedesktop.org/series/126882/
State : success

== Summary ==

+ KERNEL=/kernel
+ git clone https://gitlab.freedesktop.org/drm/maintainer-tools mt
Cloning into 'mt'...
warning: redirecting to https://gitlab.freedesktop.org/drm/maintainer-tools.git/
+ git -C mt rev-list -n1 origin/master
63c2b6b160bca2df6efc7bc4cea6f442097d7854
+ cd /kernel
+ git config --global --add safe.directory /kernel
+ git log -n1
commit 40e0960f92ed0d51fde659c73ea2a55b2888bf21
Author: Matthew Auld <matthew.auld at intel.com>
Date:   Mon Nov 27 09:44:59 2023 +0000

    drm/xe: fix mem_access for early lrc generation
    
    We spawn some hw queues during device probe to generate the default LRC
    for every engine type, however the queue destruction step is typically
    async. Queue destruction needs to do stuff like GuC context deregister
    which requires GuC CT, which in turn requires an active mem_access ref.
    The caller during probe is meant to hold the mem_access token, however
    due to the async destruction it might have already been dropped if we
    are unlucky.
    
    Similar to how we already handle migrate VMs for which there is no
    mem_access ref, fix this by keeping the callers token alive, releasing
    it only when destroying the queue. We can treat a NULL vm as indication
    that we need to grab our own extra ref.
    
    Fixes the following splat sometimes during load:
    
    [ 1682.899930] WARNING: CPU: 1 PID: 8642 at drivers/gpu/drm/xe/xe_device.c:537 xe_device_assert_mem_access+0x27/0x30 [xe]
    [ 1682.900209] CPU: 1 PID: 8642 Comm: kworker/u24:97 Tainted: G     U  W   E    N 6.6.0-rc3+ #6
    [ 1682.900214] Workqueue: submit_wq xe_sched_process_msg_work [xe]
    [ 1682.900303] RIP: 0010:xe_device_assert_mem_access+0x27/0x30 [xe]
    [ 1682.900388] Code: 90 90 90 66 0f 1f 00 0f 1f 44 00 00 53 48 89 fb e8 1e 6c 03 00 48 85 c0 74 06 5b c3 cc cc cc cc 8b 83 28 23 00 00 85 c0 75 f0 <0f> 0b 5b c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90
    [ 1682.900390] RSP: 0018:ffffc900021cfb68 EFLAGS: 00010246
    [ 1682.900394] RAX: 0000000000000000 RBX: ffff8886a96d8000 RCX: 0000000000000000
    [ 1682.900396] RDX: 0000000000000001 RSI: ffff8886a6311a00 RDI: ffff8886a96d8000
    [ 1682.900398] RBP: ffffc900021cfcc0 R08: 0000000000000001 R09: 0000000000000000
    [ 1682.900400] R10: ffffc900021cfcd0 R11: 0000000000000002 R12: 0000000000000004
    [ 1682.900402] R13: 0000000000000000 R14: ffff8886a6311990 R15: ffffc900021cfd74
    [ 1682.900405] FS:  0000000000000000(0000) GS:ffff888829880000(0000) knlGS:0000000000000000
    [ 1682.900407] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    [ 1682.900409] CR2: 000055f70bad3fb0 CR3: 000000025243a004 CR4: 00000000003706e0
    [ 1682.900412] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    [ 1682.900413] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    [ 1682.900415] Call Trace:
    [ 1682.900418]  <TASK>
    [ 1682.900420]  ? xe_device_assert_mem_access+0x27/0x30 [xe]
    [ 1682.900504]  ? __warn+0x85/0x170
    [ 1682.900510]  ? xe_device_assert_mem_access+0x27/0x30 [xe]
    [ 1682.900596]  ? report_bug+0x171/0x1a0
    [ 1682.900604]  ? handle_bug+0x3c/0x80
    [ 1682.900608]  ? exc_invalid_op+0x17/0x70
    [ 1682.900612]  ? asm_exc_invalid_op+0x1a/0x20
    [ 1682.900621]  ? xe_device_assert_mem_access+0x27/0x30 [xe]
    [ 1682.900706]  ? xe_device_assert_mem_access+0x12/0x30 [xe]
    [ 1682.900790]  guc_ct_send_locked+0xb9/0x1550 [xe]
    [ 1682.900882]  ? lock_acquire+0xca/0x2b0
    [ 1682.900885]  ? guc_ct_send+0x3c/0x1a0 [xe]
    [ 1682.900977]  ? lock_is_held_type+0x9b/0x110
    [ 1682.900984]  ? __mutex_lock+0xc0/0xb90
    [ 1682.900989]  ? __pfx___drm_printfn_info+0x10/0x10
    [ 1682.900999]  guc_ct_send+0x53/0x1a0 [xe]
    [ 1682.901090]  ? __lock_acquire+0xf22/0x21b0
    [ 1682.901097]  ? process_one_work+0x1a0/0x500
    [ 1682.901109]  xe_guc_ct_send+0x19/0x50 [xe]
    [ 1682.901202]  set_min_preemption_timeout+0x75/0xa0 [xe]
    [ 1682.901294]  disable_scheduling_deregister+0x55/0x250 [xe]
    [ 1682.901383]  ? xe_sched_process_msg_work+0x76/0xd0 [xe]
    [ 1682.901467]  ? lock_release+0xc9/0x260
    [ 1682.901474]  xe_sched_process_msg_work+0x82/0xd0 [xe]
    [ 1682.901559]  process_one_work+0x20a/0x500
    
    v2: Add the splat
    
    Signed-off-by: Matthew Auld <matthew.auld at intel.com>
    Cc: Vinay Belgaumkar <vinay.belgaumkar at intel.com>
    Cc: Matthew Brost <matthew.brost at intel.com>
    Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
+ /mt/dim checkpatch 1832821c7e4c5bd24353183f060f1435b2eb7992 drm-intel
40e0960f9 drm/xe: fix mem_access for early lrc generation