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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
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Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
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+=======================================
+Peak Tops Limiter (PTL) sysfs Interface
+=======================================
+
+Overview
+--------
+The Peak Tops Limiter (PTL) sysfs interface enables users to control and
+configure the PTL feature for each GPU individually. All PTL-related
+sysfs files are located under `/sys/class/drm/cardX/device/ptl/`, where
+`X` is the GPU index. Through these files, users can enable or disable
+PTL, set preferred data formats, and query supported formats for each GPU.
+
+PTL sysfs files
+----------------
+The following files are available under `/sys/class/drm/cardX/device/ptl/`:
+
+- `ptl_enable`
+- `ptl_format`
+- `ptl_supported_formats`
+
+PTL Enable/Disable
+------------------
+File: `ptl_enable`
+Type: Read/Write (rw)
+
+Read: Returns the current PTL status as a string: `enabled` if PTL
+is active, or `disabled` if inactive.
+
+Write:
+
+- Write `1` or `enabled` to enable PTL
+- Write `0` or `disabled` to disable PTL
+
+Examples::
+
+ # Query PTL status
+ cat /sys/class/drm/card1/device/ptl/ptl_enable
+ # Output: enabled
+
+ # Enable PTL
+ sudo bash -c "echo 1 > /sys/class/drm/card1/device/ptl/ptl_enable"
+
+ # Disable PTL
+ sudo bash -c "echo 0 > /sys/class/drm/card1/device/ptl/ptl_enable"
+
+PTL Format (Preferred Data Formats)
+-----------------------------------
+File: `ptl_format`
+Type: Read/Write (rw)
+
+Read: Returns the two preferred formats, e.g. `I8,F32`.
+
+Write: Accepts two formats separated by a comma, e.g. `I8,F32`.
+
+- Both formats must be supported and different.
+- If an invalid format is provided (not supported, or both formats are the
+ same), the driver will return "write error: Invalid argument".
+
+Examples::
+
+ # Query PTL formats
+ cat /sys/class/drm/card1/device/ptl/ptl_format
+ # Output: I8,F32
+
+ # Set PTL formats
+ sudo bash -c "echo I8,F32 > /sys/class/drm/card1/device/ptl/ptl_format"
+
+Supported Formats
+-----------------
+File: `ptl_supported_formats`
+Type: Read-only (r)
+
+Read: Returns a comma-separated list of supported formats, e.g.
+`I8,F16,BF16,F32,F64`.
+
+Example::
+
+ # Check supported formats
+ cat /sys/class/drm/card1/device/ptl/ptl_supported_formats
+ # Output: I8,F16,BF16,F32,F64
+
+Behavioral Notes
+----------------
+- PTL formats can only be set when PTL is enabled.
+- If PTL is disabled, `ptl_format` returns `N/A`.
+- Only two formats can be set at a time, and they must be from the supported set and different..
+- All commands support per-GPU targeting.
+- Root permission is required to enable/disable PTL or change formats.
+- If the hardware does not support PTL, the PTL sysfs directory will not
+ be created.
+
+Implementation
+--------------
+The PTL sysfs nodes are implemented in `drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c`.