xref: /linux/drivers/gpu/drm/i915/i915_switcheroo.c (revision f6e8dc9edf963dbc99085e54f6ced6da9daa6100)
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 
16 static 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 
47 static 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 
61 static 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 
67 int 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 
74 void 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 }
80