[Intel-gfx] [PATCH] drm/i915: apply PM_EARLY for non-GTT mappable objects

[Lucas De Marchi]

On Fri, Feb 25, 2022 at 10:34:43AM +0000, Matthew Auld wrote:
>On DG2 we allow objects that are smaller than the min_page_size, under
>the premise that these are never mapped by the GTT, like with the paging
>structures. Currently the suspend-resume path will try to map such
>objects through the migration vm, which hits:
>
>[  560.529217] kernel BUG at drivers/gpu/drm/i915/gt/intel_migrate.c:431!
>[  560.536081] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
>[  560.541629] CPU: 4 PID: 2062 Comm: rtcwake Tainted: G        W         5.17.0-rc5-demarchi+ #175
>[  560.550716] Hardware name: Intel Corporation CoffeeLake Client Platform/CoffeeLake S UDIMM RVP, BIOS CNLSFWR1.R00.X220.B00.2103302221 03/30/2021
>[  560.563627] RIP: 0010:emit_pte+0x2e7/0x380 [i915]
>[  560.568665] Code: ee 02 48 89 69 04 83 c6 05 83 c0 05 39 f0 0f 4f c6 48 8b 73 08 39 d0 0f 4f c2 44 89 f2 4c 8d 4a ff 49 85 f1 0f 84 62 fe ff ff <0f> 0b 48 c7 03 00 00 00 00 4d 89 c6 8b 01 48 29 ce 48 8d 57 0c 48
>[  560.587691] RSP: 0018:ffffc9000104f8a0 EFLAGS: 00010206
>[  560.592906] RAX: 0000000000000040 RBX: ffffc9000104f908 RCX: ffffc900025114d0
>[  560.600024] RDX: 0000000000010000 RSI: 00000003f9fe2000 RDI: ffffc900025114dc
>[  560.607458] RBP: 0000000001840000 R08: ffff88810f335540 R09: 000000000000ffff
>[  560.614865] R10: 000000000000081b R11: 0000000000000001 R12: 000000000000081b
>[  560.622300] R13: 0000000000000000 R14: 0000000000010000 R15: ffff888107c3e240
>[  560.629716] FS:  00007f5b7c086580(0000) GS:ffff88846dc00000(0000) knlGS:0000000000000000
>[  560.638090] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>[  560.644132] CR2: 00007f3ab0a133a8 CR3: 000000010a43e003 CR4: 00000000003706e0
>[  560.651590] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>[  560.659002] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>[  560.666438] Call Trace:
>[  560.668885]  <TASK>
>[  560.670983]  intel_context_migrate_copy+0x1b1/0x4c0 [i915]
>[  560.676794]  __i915_ttm_move+0x628/0x790 [i915]
>[  560.681704]  ? dma_resv_iter_next+0x8f/0xb0
>[  560.686223]  ? dma_resv_iter_first+0xe5/0x140
>[  560.690894]  ? i915_deps_add_resv+0x4b/0x110 [i915]
>[  560.696147]  ? dma_resv_reserve_shared+0x161/0x310
>[  560.701228]  i915_gem_obj_copy_ttm+0x10f/0x220 [i915]
>[  560.706650]  i915_ttm_backup+0x191/0x2f0 [i915]
>[  560.711558]  i915_gem_process_region+0x266/0x3b0 [i915]
>[  560.717153]  ? verify_cpu+0xf0/0x100
>[  560.721040]  ? pci_pm_resume_early+0x20/0x20
>[  560.725603]  i915_ttm_backup_region+0x47/0x70 [i915]
>[  560.730927]  i915_gem_backup_suspend+0x141/0x170 [i91
>
>For now let's just force the memcpy path for such objects during
>suspend-resume.
>
>Fixes: 00e27ad85bc9 ("drm/i915/migrate: add acceleration support for DG2")
>Reported-by: Lucas De Marchi <lucas.demarchi at intel.com>
>Signed-off-by: Matthew Auld <matthew.auld at intel.com>
>Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>


Reviewed-by: Lucas De Marchi <lucas.demarchi at intel.com>

thanks
Lucas De Marchi