Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-29 23:51:37 +00:00
Code Issues Packages Projects Releases Wiki Activity

drm/i915: Call acpi_video_register_backlight() (v3)

Browse Source 
On machins without an i915 opregion the acpi_video driver immediately
probes the ACPI video bus and used to also immediately register
acpi_video# backlight devices when supported.

Once the drm/kms driver then loaded later and possibly registered
a native backlight device then the drivers/acpi/video_detect.c code
unregistered the acpi_video0 device to avoid there being 2 backlight
devices (when acpi_video_get_backlight_type()==native).

This means that userspace used to briefly see 2 devices and the
disappearing of acpi_video0 after a brief time confuses the systemd
backlight level save/restore code, see e.g.:
https://bbs.archlinux.org/viewtopic.php?id=269920

To fix this the ACPI video code has been modified to make backlight class
device registration a separate step, relying on the drm/kms driver to
ask for the acpi_video backlight registration after it is done setting up
its native backlight device.

Add a call to the new acpi_video_register_backlight() after the i915 calls
acpi_video_register() (after setting up the i915 opregion) so that the
acpi_video backlight devices get registered on systems where the i915
native backlight device is not registered.

Changes in v2:
-Only call acpi_video_register_backlight() when a panel is detected

Changes in v3:
-Add a new intel_acpi_video_register() helper which checks if a panel
 is present and then calls acpi_video_register_backlight()

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Hans de Goede 2022-04-30 15:54:36 +02:00
parent 6cb634d0dc
commit 3c8b6a399e
3 changed files with 31 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/gpu/drm/i915/display/intel_acpi.c
View File

@ -7,6 +7,7 @@
#include <linux/pci.h>
#include <linux/acpi.h>
#include <acpi/video.h>
#include "i915_drv.h"
#include "intel_acpi.h"
@ -331,3 +332,29 @@ void intel_acpi_assign_connector_fwnodes(struct drm_i915_private *i915)
*/
fwnode_handle_put(fwnode);
}
void intel_acpi_video_register(struct drm_i915_private *i915)
{
struct drm_connector_list_iter conn_iter;
struct drm_connector *connector;
acpi_video_register();
/*
* If i915 is driving an internal panel without registering its native
* backlight handler try to register the acpi_video backlight.
* For panels not driven by i915 another GPU driver may still register
* a native backlight later and acpi_video_register_backlight() should
* only be called after any native backlights have been registered.
*/
drm_connector_list_iter_begin(&i915->drm, &conn_iter);
drm_for_each_connector_iter(connector, &conn_iter) {
struct intel_panel *panel = &to_intel_connector(connector)->panel;
if (panel->backlight.funcs && !panel->backlight.device) {
acpi_video_register_backlight();
break;
}
}
drm_connector_list_iter_end(&conn_iter);
}

3
drivers/gpu/drm/i915/display/intel_acpi.h
View File

@ -14,6 +14,7 @@ void intel_unregister_dsm_handler(void);
void intel_dsm_get_bios_data_funcs_supported(struct drm_i915_private *i915);
void intel_acpi_device_id_update(struct drm_i915_private *i915);
void intel_acpi_assign_connector_fwnodes(struct drm_i915_private *i915);
void intel_acpi_video_register(struct drm_i915_private *i915);
#else
static inline void intel_register_dsm_handler(void) { return; }
static inline void intel_unregister_dsm_handler(void) { return; }
@ -23,6 +24,8 @@ static inline
void intel_acpi_device_id_update(struct drm_i915_private *i915) { return; }
static inline
void intel_acpi_assign_connector_fwnodes(struct drm_i915_private *i915) { return; }
static inline
void intel_acpi_video_register(struct drm_i915_private *i915) { return; }
#endif /* CONFIG_ACPI */
#endif /* __INTEL_ACPI_H__ */

2
drivers/gpu/drm/i915/display/intel_display.c
View File

@ -9084,7 +9084,7 @@ void intel_display_driver_register(struct drm_i915_private *i915)
/* Must be done after probing outputs */
intel_opregion_register(i915);
acpi_video_register();
intel_acpi_video_register(i915);
intel_audio_init(i915);