mirror of https://github.com/torvalds/linux.git
66 lines
1.7 KiB
C
66 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0 or MIT
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#include <linux/sysrq.h>
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#include <drm/drm_client_event.h>
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#include <drm/drm_device.h>
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#include <drm/drm_print.h>
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#include "drm_internal.h"
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#ifdef CONFIG_MAGIC_SYSRQ
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static LIST_HEAD(drm_client_sysrq_dev_list);
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static DEFINE_MUTEX(drm_client_sysrq_dev_lock);
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/* emergency restore, don't bother with error reporting */
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static void drm_client_sysrq_restore_work_fn(struct work_struct *ignored)
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{
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struct drm_device *dev;
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guard(mutex)(&drm_client_sysrq_dev_lock);
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list_for_each_entry(dev, &drm_client_sysrq_dev_list, client_sysrq_list) {
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if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
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continue;
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drm_client_dev_restore(dev, true);
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}
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}
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static DECLARE_WORK(drm_client_sysrq_restore_work, drm_client_sysrq_restore_work_fn);
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static void drm_client_sysrq_restore_handler(u8 ignored)
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{
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schedule_work(&drm_client_sysrq_restore_work);
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}
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static const struct sysrq_key_op drm_client_sysrq_restore_op = {
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.handler = drm_client_sysrq_restore_handler,
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.help_msg = "force-fb(v)",
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.action_msg = "Restore framebuffer console",
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};
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void drm_client_sysrq_register(struct drm_device *dev)
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{
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guard(mutex)(&drm_client_sysrq_dev_lock);
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if (list_empty(&drm_client_sysrq_dev_list))
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register_sysrq_key('v', &drm_client_sysrq_restore_op);
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list_add(&dev->client_sysrq_list, &drm_client_sysrq_dev_list);
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}
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void drm_client_sysrq_unregister(struct drm_device *dev)
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{
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guard(mutex)(&drm_client_sysrq_dev_lock);
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/* remove device from global restore list */
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if (!drm_WARN_ON(dev, list_empty(&dev->client_sysrq_list)))
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list_del(&dev->client_sysrq_list);
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/* no devices left; unregister key */
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if (list_empty(&drm_client_sysrq_dev_list))
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unregister_sysrq_key('v', &drm_client_sysrq_restore_op);
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}
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#endif
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