xref: /linux/drivers/gpu/drm/i915/display/intel_display_reset.c (revision 22c55fb9eb92395d999b8404d73e58540d11bdd8)
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_core.h"
12 #include "intel_display_driver.h"
13 #include "intel_display_reset.h"
14 #include "intel_display_types.h"
15 #include "intel_hotplug.h"
16 #include "intel_pps.h"
17 
18 bool intel_display_reset_test(struct intel_display *display)
19 {
20 	return display->params.force_reset_modeset_test;
21 }
22 
23 /* returns true if intel_display_reset_finish() needs to be called */
24 bool intel_display_reset_prepare(struct intel_display *display,
25 				 modeset_stuck_fn modeset_stuck, void *context)
26 {
27 	struct drm_modeset_acquire_ctx *ctx = &display->restore.reset_ctx;
28 	struct drm_atomic_state *state;
29 	int ret;
30 
31 	if (!HAS_DISPLAY(display))
32 		return false;
33 
34 	if (atomic_read(&display->restore.pending_fb_pin)) {
35 		drm_dbg_kms(display->drm,
36 			    "Modeset potentially stuck, unbreaking through wedging\n");
37 		modeset_stuck(context);
38 	}
39 
40 	/*
41 	 * Need mode_config.mutex so that we don't
42 	 * trample ongoing ->detect() and whatnot.
43 	 */
44 	mutex_lock(&display->drm->mode_config.mutex);
45 	drm_modeset_acquire_init(ctx, 0);
46 	while (1) {
47 		ret = drm_modeset_lock_all_ctx(display->drm, ctx);
48 		if (ret != -EDEADLK)
49 			break;
50 
51 		drm_modeset_backoff(ctx);
52 	}
53 	/*
54 	 * Disabling the crtcs gracefully seems nicer. Also the
55 	 * g33 docs say we should at least disable all the planes.
56 	 */
57 	state = drm_atomic_helper_duplicate_state(display->drm, ctx);
58 	if (IS_ERR(state)) {
59 		ret = PTR_ERR(state);
60 		drm_err(display->drm, "Duplicating state failed with %i\n",
61 			ret);
62 		return true;
63 	}
64 
65 	ret = drm_atomic_helper_disable_all(display->drm, ctx);
66 	if (ret) {
67 		drm_err(display->drm, "Suspending crtc's failed with %i\n",
68 			ret);
69 		drm_atomic_state_put(state);
70 		return true;
71 	}
72 
73 	display->restore.modeset_state = state;
74 	state->acquire_ctx = ctx;
75 
76 	return true;
77 }
78 
79 void intel_display_reset_finish(struct intel_display *display, bool test_only)
80 {
81 	struct drm_i915_private *i915 = to_i915(display->drm);
82 	struct drm_modeset_acquire_ctx *ctx = &display->restore.reset_ctx;
83 	struct drm_atomic_state *state;
84 	int ret;
85 
86 	if (!HAS_DISPLAY(display))
87 		return;
88 
89 	state = fetch_and_zero(&display->restore.modeset_state);
90 	if (!state)
91 		goto unlock;
92 
93 	/* reset doesn't touch the display */
94 	if (test_only) {
95 		/* for testing only restore the display */
96 		ret = drm_atomic_helper_commit_duplicated_state(state, ctx);
97 		if (ret) {
98 			drm_WARN_ON(display->drm, ret == -EDEADLK);
99 			drm_err(display->drm,
100 				"Restoring old state failed with %i\n", ret);
101 		}
102 	} else {
103 		/*
104 		 * The display has been reset as well,
105 		 * so need a full re-initialization.
106 		 */
107 		intel_pps_unlock_regs_wa(display);
108 		intel_display_driver_init_hw(display);
109 		intel_clock_gating_init(i915);
110 		intel_cx0_pll_power_save_wa(display);
111 		intel_hpd_init(display);
112 
113 		ret = __intel_display_driver_resume(display, state, ctx);
114 		if (ret)
115 			drm_err(display->drm,
116 				"Restoring old state failed with %i\n", ret);
117 
118 		intel_hpd_poll_disable(display);
119 	}
120 
121 	drm_atomic_state_put(state);
122 unlock:
123 	drm_modeset_drop_locks(ctx);
124 	drm_modeset_acquire_fini(ctx);
125 	mutex_unlock(&display->drm->mode_config.mutex);
126 }
127