i915_switcheroo.c

 1// SPDX-License-Identifier: MIT
 2/*
 3 * Copyright © 2019 Intel Corporation
 4 */
 5
 6#include <linux/vga_switcheroo.h>
 7
 8#include <drm/drm_print.h>
 9
10#include "display/intel_display_device.h"
11
12#include "i915_driver.h"
13#include "i915_drv.h"
14#include "i915_switcheroo.h"
15
16static void i915_switcheroo_set_state(struct pci_dev *pdev,
17				      enum vga_switcheroo_state state)
18{
19	struct drm_i915_private *i915 = pdev_to_i915(pdev);
20	struct intel_display *display = i915 ? i915->display : NULL;
21	pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
22
23	if (!i915) {
24		dev_err(&pdev->dev, "DRM not initialized, aborting switch.\n");
25		return;
26	}
27	if (!intel_display_device_present(display)) {
28		dev_err(&pdev->dev, "Device state not initialized, aborting switch.\n");
29		return;
30	}
31
32	if (state == VGA_SWITCHEROO_ON) {
33		drm_info(&i915->drm, "switched on\n");
34		i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
35		/* i915 resume handler doesn't set to D0 */
36		pci_set_power_state(pdev, PCI_D0);
37		i915_driver_resume_switcheroo(i915);
38		i915->drm.switch_power_state = DRM_SWITCH_POWER_ON;
39	} else {
40		drm_info(&i915->drm, "switched off\n");
41		i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
42		i915_driver_suspend_switcheroo(i915, pmm);
43		i915->drm.switch_power_state = DRM_SWITCH_POWER_OFF;
44	}
45}
46
47static bool i915_switcheroo_can_switch(struct pci_dev *pdev)
48{
49	struct drm_i915_private *i915 = pdev_to_i915(pdev);
50	struct intel_display *display = i915 ? i915->display : NULL;
51
52	/*
53	 * FIXME: open_count is protected by drm_global_mutex but that would lead to
54	 * locking inversion with the driver load path. And the access here is
55	 * completely racy anyway. So don't bother with locking for now.
56	 */
57	return i915 && intel_display_device_present(display) &&
58		atomic_read(&i915->drm.open_count) == 0;
59}
60
61static const struct vga_switcheroo_client_ops i915_switcheroo_ops = {
62	.set_gpu_state = i915_switcheroo_set_state,
63	.reprobe = NULL,
64	.can_switch = i915_switcheroo_can_switch,
65};
66
67int i915_switcheroo_register(struct drm_i915_private *i915)
68{
69	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
70
71	return vga_switcheroo_register_client(pdev, &i915_switcheroo_ops, false);
72}
73
74void i915_switcheroo_unregister(struct drm_i915_private *i915)
75{
76	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
77
78	vga_switcheroo_unregister_client(pdev);
79}