lwn.git/drivers/acpi/acpi_video.c, branch v6.5

ACPI: video: Remove register_backlight_delay module option and code

2023-04-11T18:55:46+00:00

Since commit 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for creating ACPI backlight by default"), the delayed registering of acpi_video# backlight devices has been disabled by default. The few bugreports where this option was used as a workaround were all cases where the GPU driver did not call acpi_video_register_backlight() and the workaround was to pass video.register_backlight_delay=1. With the recent "ACPI: video: Make acpi_backlight=video work independent from GPU driver" changes acpi_backlight=video can be used to achieve the same result. So there is no need for the register_backlight_delay option + code anymore. Reviewed-by: Mario Limonciello Signed-off-by: Hans de Goede Signed-off-by: Rafael J. Wysocki

ACPI: video: Make acpi_backlight=video work independent from GPU driver

2023-04-05T18:23:02+00:00

Commit 3dbc80a3e4c5 ("ACPI: video: Make backlight class device registration a separate step (v2)") combined with commit 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for creating ACPI backlight by default") Means that the video.ko code now fully depends on the GPU driver calling acpi_video_register_backlight() for the acpi_video# backlight class devices to get registered. This means that if the GPU driver does not do this, acpi_backlight=video on the cmdline, or DMI quirks for selecting acpi_video# will not work. This is a problem on for example Apple iMac14,1 all-in-ones where the monitor's LCD panel shows up as a regular DP connection instead of eDP so the GPU driver will not call acpi_video_register_backlight() [1]. Fix this by making video.ko directly register the acpi_video# devices when these have been explicitly requested either on the cmdline or through DMI quirks (rather then auto-detection being used). [1] GPU drivers only call acpi_video_register_backlight() when an internal panel is detected, to avoid non working acpi_video# devices getting registered on desktops which unfortunately is a real issue. Fixes: 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for creating ACPI backlight by default") Cc: All applicable Reviewed-by: Mario Limonciello Signed-off-by: Hans de Goede Signed-off-by: Rafael J. Wysocki

ACPI: video: Don't enable fallback path for creating ACPI backlight by default

2022-12-22T16:26:42+00:00

The ACPI video detection code has a module parameter `register_backlight_delay` which is currently configured to 8 seconds. This means that if after 8 seconds of booting no native driver has created a backlight device then the code will attempt to make an ACPI video backlight device. This was intended as a safety mechanism with the backlight overhaul that occurred in kernel 6.1, but as it doesn't appear necesssary set it to be disabled by default. Suggested-by: Hans de Goede Signed-off-by: Mario Limonciello Reviewed-by: Hans de Goede Signed-off-by: Rafael J. Wysocki

ACPI: video: Allow GPU drivers to report no panels

2022-12-22T16:26:41+00:00

The current logic for the ACPI backlight detection will create a backlight device if no native or vendor drivers have created 8 seconds after the system has booted if the ACPI tables included backlight control methods. If the GPU drivers have loaded, they may be able to report whether any LCD panels were found. Allow using this information to factor in whether to enable the fallback logic for making an acpi_video0 backlight device. Suggested-by: Hans de Goede Signed-off-by: Mario Limonciello Reviewed-by: Hans de Goede Signed-off-by: Rafael J. Wysocki

ACPI: make remove callback of ACPI driver void

2022-11-23T18:11:22+00:00

For bus-based driver, device removal is implemented as: 1 device_remove()-> 2 bus->remove()-> 3 driver->remove() Driver core needs no inform from callee(bus driver) about the result of remove callback. In that case, commit fc7a6209d571 ("bus: Make remove callback return void") forces bus_type::remove be void-returned. Now we have the situation that both 1 & 2 of calling chain are void-returned, so it does not make much sense for 3(driver->remove) to return non-void to its caller. So the basic idea behind this change is making remove() callback of any bus-based driver to be void-returned. This change, for itself, is for device drivers based on acpi-bus. Acked-by: Uwe Kleine-König Acked-by: Lee Jones Acked-by: Dmitry Torokhov Reviewed-by: Hans de Goede Signed-off-by: Dawei Li Reviewed-by: Maximilian Luz # for drivers/platform/surface/* Signed-off-by: Rafael J. Wysocki

Merge tag 'platform-drivers-x86-v6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

2022-10-05T17:38:24+00:00

Pull x86 platform driver updates from Hans de Goede: - AMD Platform Management Framework (PMF) driver with AMT and QnQF support - AMD PMC: Improved logging for debugging s2idle issues - Big refactor of the ACPI/x86 backlight handling, ensuring that we only register 1 /sys/class/backlight device per LCD panel - Microsoft Surface: - Surface Laptop Go 2 support - Surface Pro 8 HID sensor support - Asus WMI: - Lots of cleanups - Support for TUF RGB keyboard backlight control - Add support for ROG X13 tablet mode - Siemens Simatic: IPC227G and IPC427G support - Toshiba ACPI laptop driver: Fan hwmon and battery ECO mode support - tools/power/x86/intel-speed-select: Various improvements - Various cleanups - Various small bugfixes * tag 'platform-drivers-x86-v6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (153 commits) platform/x86: use PLATFORM_DEVID_NONE instead of -1 platform/x86/amd: pmc: Dump idle mask during "check" stage instead platform/x86/intel/wmi: thunderbolt: Use dev_groups callback platform/x86/amd: pmc: remove CONFIG_DEBUG_FS checks platform/surface: Split memcpy() of struct ssam_event flexible array platform/x86: compal-laptop: Get rid of a few forward declarations platform/x86: intel-uncore-freq: Use sysfs_emit() to instead of scnprintf() platform/x86: dell-smbios-base: Use sysfs_emit() platform/x86/amd/pmf: Remove unused power_delta instances platform/x86/amd/pmf: install notify handler after acpi init Documentation/ABI/testing/sysfs-amd-pmf: Add ABI doc for AMD PMF platform/x86/amd/pmf: Add sysfs to toggle CnQF platform/x86/amd/pmf: Add support for CnQF platform/x86/amd: pmc: Fix build without debugfs platform/x86: hp-wmi: Support touchpad on/off platform/x86: int3472/discrete: Drop a forward declaration platform/x86: toshiba_acpi: change turn_on_panel_on_resume to static platform/x86: wmi: Drop forward declaration of static functions platform/x86: toshiba_acpi: Remove duplicate include platform/x86: msi-laptop: Change DMI match / alias strings to fix module autoloading ...

Merge branches 'acpi-ec', 'acpi-ac', 'acpi-fan', 'acpi-video' and 'acpi-amba'

2022-10-03T17:59:47+00:00

Merge EC, AC, fan and backlight driver changes and ACPI AMBA support update for 6.1-rc1: - Drop unneeded result variable from ec_write() (ye xingchen). - Remove the leftover struct acpi_ac_bl from the ACPI AC driver (Hanjun Guo). - Reorder symbols to get rid of a few forward declarations in the ACPI fan driver (Uwe Kleine-König). - Add Toshiba Satellite/Portege Z830 ACPI backlight quirk (Arvid Norlander). - Add ARM DMA-330 controller to the supported list in the ACPI AMBA driver (Vijayenthiran Subramaniam). * acpi-ec: ACPI: EC: Drop unneeded result variable from ec_write() * acpi-ac: ACPI: AC: Remove the leftover struct acpi_ac_bl * acpi-fan: ACPI: fan: Reorder symbols to get rid of a few forward declarations * acpi-video: ACPI: video: Add Toshiba Satellite/Portege Z830 quirk * acpi-amba: ACPI: AMBA: Add ARM DMA-330 controller to the supported list

ACPI: video: Change disable_backlight_sysfs_if quirks to acpi_backlight=native

2022-09-09T19:58:16+00:00

Some Toshibas have a broken acpi-video interface for brightness control and need a special firmware call on resume to turn the panel back on. So far these have been using the disable_backlight_sysfs_if workaround to deal with this. The recent x86/acpi backlight refactoring has broken this workaround: 1. This workaround relies on acpi_video_get_backlight_type() returning acpi_video so that the acpi_video code actually runs; and 2. this relies on the actual native GPU driver to offer the sysfs backlight interface to userspace. After the refactor this breaks since the native driver will no longer register its backlight-device if acpi_video_get_backlight_type() does not return native and making it return native breaks 1. Keeping the acpi_video backlight handling on resume active, while not using it to set the brightness, is necessary because it does a _BCM call on resume which is necessary to turn the panel back on on resume. Looking at the DSDT shows that this _BCM call results in a Toshiba HCI_SET HCI_LCD_BRIGHTNESS call, which turns the panel back on. This kind of special vendor specific handling really belongs in the vendor specific acpi driver. An earlier patch in this series modifies toshiba_acpi to make the necessary HCI_SET call on resume on affected models. With toshiba_acpi taking care of the HCI_SET call on resume, the acpi_video code no longer needs to call _BCM on resume. So instead of using the (now broken) disable_backlight_sysfs_if workaround, simply setting acpi_backlight=native to disable the broken apci-video interface is sufficient fix things now. After this there are no more users of the disable_backlight_sysfs_if flag and as discussed above the flag also no longer works as intended, so remove the disable_backlight_sysfs_if flag entirely. Acked-by: Rafael J. Wysocki Tested-by: Arvid Norlander Signed-off-by: Hans de Goede

ACPI: video: Add Toshiba Satellite/Portege Z830 quirk

2022-09-03T18:28:33+00:00

Toshiba Satellite Z830 needs the quirk video_disable_backlight_sysfs_if for proper backlight control after suspend/resume cycles. Toshiba Portege Z830 is simply the same laptop rebranded for certain markets (I looked through the manual to other language sections to confirm this) and thus also needs this quirk. Thanks to Hans de Goede for suggesting this fix. Link: https://www.spinics.net/lists/platform-driver-x86/msg34394.html Suggested-by: Hans de Goede Signed-off-by: Arvid Norlander Reviewed-by: Hans de Goede Tested-by: Arvid Norlander Signed-off-by: Rafael J. Wysocki

ACPI: video: Remove acpi_video_set_dmi_backlight_type()

2022-09-03T10:17:27+00:00

acpi_video_set_dmi_backlight_type() is troublesome because it may end up getting called after other backlight drivers have already called acpi_video_get_backlight_type() resulting in the other drivers already being registered even though they should not. In case of the acpi_video backlight, acpi_video_set_dmi_backlight_type() actually calls acpi_video_unregister_backlight() since that is often probed earlier, leading to userspace seeing the acpi_video0 class device being briefly available, leading to races in userspace where udev probe-rules try to access the device and it is already gone. All callers have been fixed to no longer call it, so remove acpi_video_set_dmi_backlight_type() now. This means we now also no longer need acpi_video_unregister_backlight() for the remove acpi_video backlight after it was wrongly registered hack, so remove that too. Acked-by: Rafael J. Wysocki Signed-off-by: Hans de Goede