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_cx0_phy.h"
11 #include "intel_display_driver.h"
12 #include "intel_display_reset.h"
13 #include "intel_display_types.h"
14 #include "intel_hotplug.h"
15 #include "intel_pps.h"
16 
intel_display_reset_test(struct intel_display * display)17 bool intel_display_reset_test(struct intel_display *display)
18 {
19 	return display->params.force_reset_modeset_test;
20 }
21 
22 /* returns true if intel_display_reset_finish() needs to be called */
intel_display_reset_prepare(struct intel_display * display,modeset_stuck_fn modeset_stuck,void * context)23 bool intel_display_reset_prepare(struct intel_display *display,
24 				 modeset_stuck_fn modeset_stuck, void *context)
25 {
26 	struct drm_modeset_acquire_ctx *ctx = &display->restore.reset_ctx;
27 	struct drm_atomic_state *state;
28 	int ret;
29 
30 	if (!HAS_DISPLAY(display))
31 		return false;
32 
33 	if (atomic_read(&display->restore.pending_fb_pin)) {
34 		drm_dbg_kms(display->drm,
35 			    "Modeset potentially stuck, unbreaking through wedging\n");
36 		modeset_stuck(context);
37 	}
38 
39 	/*
40 	 * Need mode_config.mutex so that we don't
41 	 * trample ongoing ->detect() and whatnot.
42 	 */
43 	mutex_lock(&display->drm->mode_config.mutex);
44 	drm_modeset_acquire_init(ctx, 0);
45 	while (1) {
46 		ret = drm_modeset_lock_all_ctx(display->drm, ctx);
47 		if (ret != -EDEADLK)
48 			break;
49 
50 		drm_modeset_backoff(ctx);
51 	}
52 	/*
53 	 * Disabling the crtcs gracefully seems nicer. Also the
54 	 * g33 docs say we should at least disable all the planes.
55 	 */
56 	state = drm_atomic_helper_duplicate_state(display->drm, ctx);
57 	if (IS_ERR(state)) {
58 		ret = PTR_ERR(state);
59 		drm_err(display->drm, "Duplicating state failed with %i\n",
60 			ret);
61 		return true;
62 	}
63 
64 	ret = drm_atomic_helper_disable_all(display->drm, ctx);
65 	if (ret) {
66 		drm_err(display->drm, "Suspending crtc's failed with %i\n",
67 			ret);
68 		drm_atomic_state_put(state);
69 		return true;
70 	}
71 
72 	display->restore.modeset_state = state;
73 	state->acquire_ctx = ctx;
74 
75 	return true;
76 }
77 
intel_display_reset_finish(struct intel_display * display,bool test_only)78 void intel_display_reset_finish(struct intel_display *display, bool test_only)
79 {
80 	struct drm_i915_private *i915 = to_i915(display->drm);
81 	struct drm_modeset_acquire_ctx *ctx = &display->restore.reset_ctx;
82 	struct drm_atomic_state *state;
83 	int ret;
84 
85 	if (!HAS_DISPLAY(display))
86 		return;
87 
88 	state = fetch_and_zero(&display->restore.modeset_state);
89 	if (!state)
90 		goto unlock;
91 
92 	/* reset doesn't touch the display */
93 	if (test_only) {
94 		/* for testing only restore the display */
95 		ret = drm_atomic_helper_commit_duplicated_state(state, ctx);
96 		if (ret) {
97 			drm_WARN_ON(display->drm, ret == -EDEADLK);
98 			drm_err(display->drm,
99 				"Restoring old state failed with %i\n", ret);
100 		}
101 	} else {
102 		/*
103 		 * The display has been reset as well,
104 		 * so need a full re-initialization.
105 		 */
106 		intel_pps_unlock_regs_wa(display);
107 		intel_display_driver_init_hw(display);
108 		intel_clock_gating_init(i915);
109 		intel_cx0_pll_power_save_wa(display);
110 		intel_hpd_init(i915);
111 
112 		ret = __intel_display_driver_resume(display, state, ctx);
113 		if (ret)
114 			drm_err(display->drm,
115 				"Restoring old state failed with %i\n", ret);
116 
117 		intel_hpd_poll_disable(i915);
118 	}
119 
120 	drm_atomic_state_put(state);
121 unlock:
122 	drm_modeset_drop_locks(ctx);
123 	drm_modeset_acquire_fini(ctx);
124 	mutex_unlock(&display->drm->mode_config.mutex);
125 }
126