diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-amd-pmc | 13 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-amd-pmf | 13 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-power | 5 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-platform-asus-wmi | 41 | ||||
| -rw-r--r-- | Documentation/gpu/todo.rst | 68 |
5 files changed, 139 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-amd-pmc b/Documentation/ABI/testing/sysfs-amd-pmc new file mode 100644 index 000000000000..c421b72844f1 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-amd-pmc @@ -0,0 +1,13 @@ +What: /sys/bus/platform/drivers/amd_pmc/*/smu_fw_version +Date: October 2022 +Contact: Mario Limonciello <mario.limonciello@amd.com> +Description: Reading this file reports the version of the firmware loaded to + System Management Unit (SMU) contained in AMD CPUs and + APUs. + +What: /sys/bus/platform/drivers/amd_pmc/*/smu_program +Date: October 2022 +Contact: Mario Limonciello <mario.limonciello@amd.com> +Description: Reading this file reports the program corresponding to the SMU + firmware version. The program field is used to disambiguate two + APU/CPU models that can share the same firmware binary. diff --git a/Documentation/ABI/testing/sysfs-amd-pmf b/Documentation/ABI/testing/sysfs-amd-pmf new file mode 100644 index 000000000000..7fc0e1c2b76b --- /dev/null +++ b/Documentation/ABI/testing/sysfs-amd-pmf @@ -0,0 +1,13 @@ +What: /sys/devices/platform/*/cnqf_enable +Date: September 2022 +Contact: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> +Description: Reading this file tells if the AMD Platform Management(PMF) + Cool n Quiet Framework(CnQF) feature is enabled or not. + + This feature is not enabled by default and gets only turned on + if OEM BIOS passes a "flag" to PMF ACPI function (index 11 or 12) + or in case the user writes "on". + + To turn off CnQF user can write "off" to the sysfs node. + Note: Systems that support auto mode will not have this sysfs file + available. diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power index a9ce63cfbe87..e434fc523291 100644 --- a/Documentation/ABI/testing/sysfs-class-power +++ b/Documentation/ABI/testing/sysfs-class-power @@ -364,7 +364,10 @@ Date: April 2019 Contact: linux-pm@vger.kernel.org Description: Represents a battery percentage level, above which charging will - stop. + stop. Not all hardware is capable of setting this to an arbitrary + percentage. Drivers will round written values to the nearest + supported value. Reading back the value will show the actual + threshold set by the driver. Access: Read, Write diff --git a/Documentation/ABI/testing/sysfs-platform-asus-wmi b/Documentation/ABI/testing/sysfs-platform-asus-wmi index 04885738cf15..a77a004a1baa 100644 --- a/Documentation/ABI/testing/sysfs-platform-asus-wmi +++ b/Documentation/ABI/testing/sysfs-platform-asus-wmi @@ -57,3 +57,44 @@ Description: * 0 - default, * 1 - overboost, * 2 - silent + +What: /sys/devices/platform/<platform>/gpu_mux_mode +Date: Aug 2022 +KernelVersion: 6.1 +Contact: "Luke Jones" <luke@ljones.dev> +Description: + Switch the GPU hardware MUX mode. Laptops with this feature can + can be toggled to boot with only the dGPU (discrete mode) or in + standard Optimus/Hybrid mode. On switch a reboot is required: + + * 0 - Discrete GPU, + * 1 - Optimus/Hybrid, + +What: /sys/devices/platform/<platform>/dgpu_disable +Date: Aug 2022 +KernelVersion: 5.17 +Contact: "Luke Jones" <luke@ljones.dev> +Description: + Disable discrete GPU: + * 0 - Enable dGPU, + * 1 - Disable dGPU + +What: /sys/devices/platform/<platform>/egpu_enable +Date: Aug 2022 +KernelVersion: 5.17 +Contact: "Luke Jones" <luke@ljones.dev> +Description: + Enable the external GPU paired with ROG X-Flow laptops. + Toggling this setting will also trigger ACPI to disable the dGPU: + + * 0 - Disable, + * 1 - Enable + +What: /sys/devices/platform/<platform>/panel_od +Date: Aug 2022 +KernelVersion: 5.17 +Contact: "Luke Jones" <luke@ljones.dev> +Description: + Enable an LCD response-time boost to reduce or remove ghosting: + * 0 - Disable, + * 1 - Enable diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 513b20ccef1e..7ff89559b3b7 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -715,6 +715,74 @@ Contact: Sam Ravnborg Level: Advanced +Brightness handling on devices with multiple internal panels +============================================================ + +On x86/ACPI devices there can be multiple backlight firmware interfaces: +(ACPI) video, vendor specific and others. As well as direct/native (PWM) +register programming by the KMS driver. + +To deal with this backlight drivers used on x86/ACPI call +acpi_video_get_backlight_type() which has heuristics (+quirks) to select +which backlight interface to use; and backlight drivers which do not match +the returned type will not register themselves, so that only one backlight +device gets registered (in a single GPU setup, see below). + +At the moment this more or less assumes that there will only +be 1 (internal) panel on a system. + +On systems with 2 panels this may be a problem, depending on +what interface acpi_video_get_backlight_type() selects: + +1. native: in this case the KMS driver is expected to know which backlight + device belongs to which output so everything should just work. +2. video: this does support controlling multiple backlights, but some work + will need to be done to get the output <-> backlight device mapping + +The above assumes both panels will require the same backlight interface type. +Things will break on systems with multiple panels where the 2 panels need +a different type of control. E.g. one panel needs ACPI video backlight control, +where as the other is using native backlight control. Currently in this case +only one of the 2 required backlight devices will get registered, based on +the acpi_video_get_backlight_type() return value. + +If this (theoretical) case ever shows up, then supporting this will need some +work. A possible solution here would be to pass a device and connector-name +to acpi_video_get_backlight_type() so that it can deal with this. + +Note in a way we already have a case where userspace sees 2 panels, +in dual GPU laptop setups with a mux. On those systems we may see +either 2 native backlight devices; or 2 native backlight devices. + +Userspace already has code to deal with this by detecting if the related +panel is active (iow which way the mux between the GPU and the panels +points) and then uses that backlight device. Userspace here very much +assumes a single panel though. It picks only 1 of the 2 backlight devices +and then only uses that one. + +Note that all userspace code (that I know off) is currently hardcoded +to assume a single panel. + +Before the recent changes to not register multiple (e.g. video + native) +/sys/class/backlight devices for a single panel (on a single GPU laptop), +userspace would see multiple backlight devices all controlling the same +backlight. + +To deal with this userspace had to always picks one preferred device under +/sys/class/backlight and will ignore the others. So to support brightness +control on multiple panels userspace will need to be updated too. + +There are plans to allow brightness control through the KMS API by adding +a "display brightness" property to drm_connector objects for panels. This +solves a number of issues with the /sys/class/backlight API, including not +being able to map a sysfs backlight device to a specific connector. Any +userspace changes to add support for brightness control on devices with +multiple panels really should build on top of this new KMS property. + +Contact: Hans de Goede + +Level: Advanced + Outside DRM =========== |