drm/i915: Always wrap the ring offset before resetting

We were passing in an unwrapped offset into intel_ring_reset() on
unpinning. Sooner or later that had to land on ring->size.

<3> [314.872147] intel_ring_reset:1237 GEM_BUG_ON(!intel_ring_offset_valid(ring, tail))
<4> [314.872272] ------------[ cut here ]------------
<2> [314.872276] kernel BUG at drivers/gpu/drm/i915/gt/intel_ringbuffer.c:1237!
<4> [314.872320] invalid opcode: 0000 [#1] PREEMPT SMP PTI
<4> [314.872331] CPU: 1 PID: 3466 Comm: i915_selftest Tainted: G     U            5.3.0-rc4-CI-Patchwork_14061+ #1
<4> [314.872346] Hardware name: Hewlett-Packard HP Compaq 8000 Elite CMT PC/3647h, BIOS 786G7 v01.02 10/22/2009
<4> [314.872477] RIP: 0010:intel_ring_reset+0x51/0x70 [i915]
<4> [314.872487] Code: 9e db 51 e0 48 8b 35 b6 c7 22 00 49 c7 c0 f8 d9 d6 a0 b9 d5 04 00 00 48 c7 c2 70 5b d4 a0 48 c7 c7 6c fc c0 a0 e8 cf be 58 e0 <0f> 0b 89 77 20 89 77 1c 89 77 24 e9 4f ed ff ff 0f 1f 44 00 00 66
<4> [314.872512] RSP: 0018:ffffc9000034fa98 EFLAGS: 00010282
<4> [314.872523] RAX: 0000000000000010 RBX: ffff8881019412c8 RCX: 0000000000000000
<4> [314.872534] RDX: 0000000000000001 RSI: 0000000000000008 RDI: 0000000000000f20
<4> [314.872545] RBP: ffff888104e0f740 R08: 0000000000000000 R09: 0000000000000f20
<4> [314.872557] R10: 0000000000000000 R11: ffff888117094518 R12: ffffffffa0d3d2c0
<4> [314.872569] R13: ffffffffa0e2a250 R14: ffffffffa0e2a1e0 R15: ffffc9000034fe88
<4> [314.872581] FS:  00007fe6d49f6e40(0000) GS:ffff888117a80000(0000) knlGS:0000000000000000
<4> [314.872595] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4> [314.872605] CR2: 000055e3283e9cc8 CR3: 0000000108842000 CR4: 00000000000406e0
<4> [314.872616] Call Trace:
<4> [314.872701]  intel_ring_unpin+0x1a/0x220 [i915]
<4> [314.872787]  ring_destroy+0x48/0xc0 [i915]
<4> [314.872870]  intel_engines_cleanup+0x24/0x40 [i915]
<4> [314.872964]  i915_gem_driver_release+0x1b/0xf0 [i915]
<4> [314.872984]  i915_driver_release+0x1c/0x80 [i915]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190819075835.20065-2-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_ringbuffer.c

@@ -1234,8 +1234,7 @@ int intel_ring_pin(struct intel_ring *ring)
 
 void intel_ring_reset(struct intel_ring *ring, u32 tail)
 {
-	GEM_BUG_ON(!intel_ring_offset_valid(ring, tail));
-
+	tail = intel_ring_wrap(ring, tail);
 	ring->tail = tail;
 	ring->head = tail;
 	ring->emit = tail;