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authorAndi Shyti <andi.shyti@linux.intel.com>2026-08-22 14:19:12 +0200
committerAndi Shyti <andi.shyti@linux.intel.com>2026-08-22 14:19:34 +0200
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Merge tag 'rust-i2c-for-7.3' into i2c/i2cgrafted
i2c: rust: mark I2cAdapter methods as inline A single cleanup for the Rust I2C abstractions, targeting 7.3. `I2cAdapter::get`, `inc_ref`, and `dec_ref` are trivial wrappers around `i2c_get_adapter`/`i2c_put_adapter` and were showing up as their own symbols in the build. Mark them `#[inline]` so they get folded into their callers instead. Signed-off-by: Igor Korotin <igor.korotin@linux.dev> * tag 'rust-i2c-for-7.3': i2c: rust: mark I2cAdapter methods as inline
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+======================
+FunctionFS Descriptors
+======================
+
+Some of the descriptors that can be written to the FFS gadget are
+described below. Device and configuration descriptors are handled
+by the composite gadget and are not written by the user to the
+FFS gadget.
+
+Descriptors are written to the "ep0" file in the FFS gadget
+following the descriptor header.
+
+.. kernel-doc:: include/uapi/linux/usb/functionfs.h
+ :doc: descriptors
+
+Interface Descriptors
+---------------------
+
+Standard USB interface descriptors may be written. The class/subclass of the
+most recent interface descriptor determines what type of class-specific
+descriptors are accepted.
+
+Class-Specific Descriptors
+--------------------------
+
+Class-specific descriptors are accepted only for the class/subclass of the
+most recent interface descriptor. The following are some of the
+class-specific descriptors that are supported.
+
+DFU Functional Descriptor
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When the interface class is USB_CLASS_APP_SPEC and the interface subclass
+is USB_SUBCLASS_DFU, a DFU functional descriptor can be provided.
+The DFU functional descriptor is a described in the USB specification for
+Device Firmware Upgrade (DFU), version 1.1 as of this writing.
+
+.. kernel-doc:: include/uapi/linux/usb/functionfs.h
+ :doc: usb_dfu_functional_descriptor