xref: /linux/drivers/gpu/drm/i915/i915_switcheroo.c (revision 68a052239fc4b351e961f698b824f7654a346091)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2019 Intel Corporation
4  */
5 
6 #include <linux/vga_switcheroo.h>
7 
8 #include "display/intel_display_device.h"
9 
10 #include "i915_driver.h"
11 #include "i915_drv.h"
12 #include "i915_switcheroo.h"
13 
14 static void i915_switcheroo_set_state(struct pci_dev *pdev,
15 				      enum vga_switcheroo_state state)
16 {
17 	struct drm_i915_private *i915 = pdev_to_i915(pdev);
18 	struct intel_display *display = i915 ? i915->display : NULL;
19 	pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
20 
21 	if (!i915) {
22 		dev_err(&pdev->dev, "DRM not initialized, aborting switch.\n");
23 		return;
24 	}
25 	if (!intel_display_device_present(display)) {
26 		dev_err(&pdev->dev, "Device state not initialized, aborting switch.\n");
27 		return;
28 	}
29 
30 	if (state == VGA_SWITCHEROO_ON) {
31 		drm_info(&i915->drm, "switched on\n");
32 		i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
33 		/* i915 resume handler doesn't set to D0 */
34 		pci_set_power_state(pdev, PCI_D0);
35 		i915_driver_resume_switcheroo(i915);
36 		i915->drm.switch_power_state = DRM_SWITCH_POWER_ON;
37 	} else {
38 		drm_info(&i915->drm, "switched off\n");
39 		i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
40 		i915_driver_suspend_switcheroo(i915, pmm);
41 		i915->drm.switch_power_state = DRM_SWITCH_POWER_OFF;
42 	}
43 }
44 
45 static bool i915_switcheroo_can_switch(struct pci_dev *pdev)
46 {
47 	struct drm_i915_private *i915 = pdev_to_i915(pdev);
48 	struct intel_display *display = i915 ? i915->display : NULL;
49 
50 	/*
51 	 * FIXME: open_count is protected by drm_global_mutex but that would lead to
52 	 * locking inversion with the driver load path. And the access here is
53 	 * completely racy anyway. So don't bother with locking for now.
54 	 */
55 	return i915 && intel_display_device_present(display) &&
56 		atomic_read(&i915->drm.open_count) == 0;
57 }
58 
59 static const struct vga_switcheroo_client_ops i915_switcheroo_ops = {
60 	.set_gpu_state = i915_switcheroo_set_state,
61 	.reprobe = NULL,
62 	.can_switch = i915_switcheroo_can_switch,
63 };
64 
65 int i915_switcheroo_register(struct drm_i915_private *i915)
66 {
67 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
68 
69 	return vga_switcheroo_register_client(pdev, &i915_switcheroo_ops, false);
70 }
71 
72 void i915_switcheroo_unregister(struct drm_i915_private *i915)
73 {
74 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
75 
76 	vga_switcheroo_unregister_client(pdev);
77 }
78