1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2023 Intel Corporation
4 */
5
6#include <drm/drm_atomic_helper.h>
7
8#include "i915_drv.h"
9#include "intel_clock_gating.h"
10#include "intel_display_driver.h"
11#include "intel_display_reset.h"
12#include "intel_display_types.h"
13#include "intel_hotplug.h"
14#include "intel_pps.h"
15
16static bool gpu_reset_clobbers_display(struct drm_i915_private *dev_priv)
17{
18 return (INTEL_INFO(dev_priv)->gpu_reset_clobbers_display &&
19 intel_has_gpu_reset(gt: to_gt(i915: dev_priv)));
20}
21
22void intel_display_reset_prepare(struct drm_i915_private *dev_priv)
23{
24 struct drm_modeset_acquire_ctx *ctx = &dev_priv->display.restore.reset_ctx;
25 struct drm_atomic_state *state;
26 int ret;
27
28 if (!HAS_DISPLAY(dev_priv))
29 return;
30
31 /* reset doesn't touch the display */
32 if (!dev_priv->display.params.force_reset_modeset_test &&
33 !gpu_reset_clobbers_display(dev_priv))
34 return;
35
36 /* We have a modeset vs reset deadlock, defensively unbreak it. */
37 set_bit(I915_RESET_MODESET, addr: &to_gt(i915: dev_priv)->reset.flags);
38 smp_mb__after_atomic();
39 wake_up_bit(word: &to_gt(i915: dev_priv)->reset.flags, I915_RESET_MODESET);
40
41 if (atomic_read(v: &dev_priv->gpu_error.pending_fb_pin)) {
42 drm_dbg_kms(&dev_priv->drm,
43 "Modeset potentially stuck, unbreaking through wedging\n");
44 intel_gt_set_wedged(gt: to_gt(i915: dev_priv));
45 }
46
47 /*
48 * Need mode_config.mutex so that we don't
49 * trample ongoing ->detect() and whatnot.
50 */
51 mutex_lock(&dev_priv->drm.mode_config.mutex);
52 drm_modeset_acquire_init(ctx, flags: 0);
53 while (1) {
54 ret = drm_modeset_lock_all_ctx(dev: &dev_priv->drm, ctx);
55 if (ret != -EDEADLK)
56 break;
57
58 drm_modeset_backoff(ctx);
59 }
60 /*
61 * Disabling the crtcs gracefully seems nicer. Also the
62 * g33 docs say we should at least disable all the planes.
63 */
64 state = drm_atomic_helper_duplicate_state(dev: &dev_priv->drm, ctx);
65 if (IS_ERR(ptr: state)) {
66 ret = PTR_ERR(ptr: state);
67 drm_err(&dev_priv->drm, "Duplicating state failed with %i\n",
68 ret);
69 return;
70 }
71
72 ret = drm_atomic_helper_disable_all(dev: &dev_priv->drm, ctx);
73 if (ret) {
74 drm_err(&dev_priv->drm, "Suspending crtc's failed with %i\n",
75 ret);
76 drm_atomic_state_put(state);
77 return;
78 }
79
80 dev_priv->display.restore.modeset_state = state;
81 state->acquire_ctx = ctx;
82}
83
84void intel_display_reset_finish(struct drm_i915_private *i915)
85{
86 struct drm_modeset_acquire_ctx *ctx = &i915->display.restore.reset_ctx;
87 struct drm_atomic_state *state;
88 int ret;
89
90 if (!HAS_DISPLAY(i915))
91 return;
92
93 /* reset doesn't touch the display */
94 if (!test_bit(I915_RESET_MODESET, &to_gt(i915)->reset.flags))
95 return;
96
97 state = fetch_and_zero(&i915->display.restore.modeset_state);
98 if (!state)
99 goto unlock;
100
101 /* reset doesn't touch the display */
102 if (!gpu_reset_clobbers_display(dev_priv: i915)) {
103 /* for testing only restore the display */
104 ret = drm_atomic_helper_commit_duplicated_state(state, ctx);
105 if (ret) {
106 drm_WARN_ON(&i915->drm, ret == -EDEADLK);
107 drm_err(&i915->drm,
108 "Restoring old state failed with %i\n", ret);
109 }
110 } else {
111 /*
112 * The display has been reset as well,
113 * so need a full re-initialization.
114 */
115 intel_pps_unlock_regs_wa(i915);
116 intel_display_driver_init_hw(i915);
117 intel_clock_gating_init(i915);
118 intel_hpd_init(dev_priv: i915);
119
120 ret = __intel_display_driver_resume(i915, state, ctx);
121 if (ret)
122 drm_err(&i915->drm,
123 "Restoring old state failed with %i\n", ret);
124
125 intel_hpd_poll_disable(dev_priv: i915);
126 }
127
128 drm_atomic_state_put(state);
129unlock:
130 drm_modeset_drop_locks(ctx);
131 drm_modeset_acquire_fini(ctx);
132 mutex_unlock(lock: &i915->drm.mode_config.mutex);
133
134 clear_bit_unlock(I915_RESET_MODESET, addr: &to_gt(i915)->reset.flags);
135}
136

source code of linux/drivers/gpu/drm/i915/display/intel_display_reset.c