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->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, &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 intel_display *display = &i915->display;
 87	struct drm_modeset_acquire_ctx *ctx = &display->restore.reset_ctx;
 88	struct drm_atomic_state *state;
 89	int ret;
 90
 91	if (!HAS_DISPLAY(i915))
 92		return;
 93
 94	/* reset doesn't touch the display */
 95	if (!test_bit(I915_RESET_MODESET, &to_gt(i915)->reset.flags))
 96		return;
 97
 98	state = fetch_and_zero(&display->restore.modeset_state);
 99	if (!state)
100		goto unlock;
101
102	/* reset doesn't touch the display */
103	if (!gpu_reset_clobbers_display(i915)) {
104		/* for testing only restore the display */
105		ret = drm_atomic_helper_commit_duplicated_state(state, ctx);
106		if (ret) {
107			drm_WARN_ON(&i915->drm, ret == -EDEADLK);
108			drm_err(&i915->drm,
109				"Restoring old state failed with %i\n", ret);
110		}
111	} else {
112		/*
113		 * The display has been reset as well,
114		 * so need a full re-initialization.
115		 */
116		intel_pps_unlock_regs_wa(display);
117		intel_display_driver_init_hw(i915);
118		intel_clock_gating_init(i915);
119		intel_hpd_init(i915);
120
121		ret = __intel_display_driver_resume(i915, state, ctx);
122		if (ret)
123			drm_err(&i915->drm,
124				"Restoring old state failed with %i\n", ret);
125
126		intel_hpd_poll_disable(i915);
127	}
128
129	drm_atomic_state_put(state);
130unlock:
131	drm_modeset_drop_locks(ctx);
132	drm_modeset_acquire_fini(ctx);
133	mutex_unlock(&i915->drm.mode_config.mutex);
134
135	clear_bit_unlock(I915_RESET_MODESET, &to_gt(i915)->reset.flags);
136}