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(to_gt(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->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, &to_gt(dev_priv)->reset.flags);
38	smp_mb__after_atomic();
39	wake_up_bit(&to_gt(dev_priv)->reset.flags, I915_RESET_MODESET);
40
41	if (atomic_read(&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(to_gt(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, 0);
53	while (1) {
54		ret = drm_modeset_lock_all_ctx(&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_priv->drm, ctx);
65	if (IS_ERR(state)) {
66		ret = PTR_ERR(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_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(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(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(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(&i915->drm.mode_config.mutex);
133
134	clear_bit_unlock(I915_RESET_MODESET, &to_gt(i915)->reset.flags);
135}
136