linux-stable/drivers/gpu/drm/i915/i915_switcheroo.c
Thomas Zimmermann a273e95721 drm/i915: Allow switching away via vga-switcheroo if uninitialized
Always allow switching away via vga-switcheroo if the display is
uninitalized. Instead prevent switching to i915 if the device has
not been initialized.

This issue was introduced by commit 5df7bd1308 ("drm/i915: skip
display initialization when there is no display") protected, which
protects code paths from being executed on uninitialized devices.
In the case of vga-switcheroo, we want to allow a switch away from
i915's device. So run vga_switcheroo_process_delayed_switch() and
test in the switcheroo callbacks if the i915 device is available.

Fixes: 5df7bd1308 ("drm/i915: skip display initialization when there is no display")
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: "Jouni Högander" <jouni.hogander@intel.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Ramalingam C <ramalingam.c@intel.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: "José Roberto de Souza" <jose.souza@intel.com>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Cc: intel-gfx@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.14+
Link: https://patchwork.freedesktop.org/patch/msgid/20230116115425.13484-2-tzimmermann@suse.de
2023-01-18 17:12:23 +01:00

72 lines
2 KiB
C

// SPDX-License-Identifier: MIT
/*
* Copyright © 2019 Intel Corporation
*/
#include <linux/vga_switcheroo.h>
#include "i915_driver.h"
#include "i915_drv.h"
#include "i915_switcheroo.h"
static void i915_switcheroo_set_state(struct pci_dev *pdev,
enum vga_switcheroo_state state)
{
struct drm_i915_private *i915 = pdev_to_i915(pdev);
pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
if (!i915) {
dev_err(&pdev->dev, "DRM not initialized, aborting switch.\n");
return;
}
if (!HAS_DISPLAY(i915)) {
dev_err(&pdev->dev, "Device state not initialized, aborting switch.\n");
return;
}
if (state == VGA_SWITCHEROO_ON) {
drm_info(&i915->drm, "switched on\n");
i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
/* i915 resume handler doesn't set to D0 */
pci_set_power_state(pdev, PCI_D0);
i915_driver_resume_switcheroo(i915);
i915->drm.switch_power_state = DRM_SWITCH_POWER_ON;
} else {
drm_info(&i915->drm, "switched off\n");
i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
i915_driver_suspend_switcheroo(i915, pmm);
i915->drm.switch_power_state = DRM_SWITCH_POWER_OFF;
}
}
static bool i915_switcheroo_can_switch(struct pci_dev *pdev)
{
struct drm_i915_private *i915 = pdev_to_i915(pdev);
/*
* FIXME: open_count is protected by drm_global_mutex but that would lead to
* locking inversion with the driver load path. And the access here is
* completely racy anyway. So don't bother with locking for now.
*/
return i915 && HAS_DISPLAY(i915) && atomic_read(&i915->drm.open_count) == 0;
}
static const struct vga_switcheroo_client_ops i915_switcheroo_ops = {
.set_gpu_state = i915_switcheroo_set_state,
.reprobe = NULL,
.can_switch = i915_switcheroo_can_switch,
};
int i915_switcheroo_register(struct drm_i915_private *i915)
{
struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
return vga_switcheroo_register_client(pdev, &i915_switcheroo_ops, false);
}
void i915_switcheroo_unregister(struct drm_i915_private *i915)
{
struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
vga_switcheroo_unregister_client(pdev);
}