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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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tree27614d7a9ef05c32d089004e104364ce42324837 /Documentation/ABI/testing/sysfs-bus-css
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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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+What: /sys/bus/css/devices/.../type
+Date: March 2008
+Contact: linux-s390@vger.kernel.org
+Description: Contains the subchannel type, as reported by the hardware.
+ This attribute is present for all subchannel types.
+
+What: /sys/bus/css/devices/.../modalias
+Date: March 2008
+Contact: linux-s390@vger.kernel.org
+Description: Contains the module alias as reported with uevents.
+ It is of the format css:t<type> and present for all
+ subchannel types.
+
+What: /sys/bus/css/drivers/io_subchannel/.../chpids
+Date: December 2002
+Contact: linux-s390@vger.kernel.org
+Description: Contains the ids of the channel paths used by this
+ subchannel, as reported by the channel subsystem
+ during subchannel recognition.
+
+ Note: This is an I/O-subchannel specific attribute.
+Users: s390-tools, HAL
+
+What: /sys/bus/css/drivers/io_subchannel/.../pimpampom
+Date: December 2002
+Contact: linux-s390@vger.kernel.org
+Description: Contains the PIM/PAM/POM values, as reported by the
+ channel subsystem when last queried by the common I/O
+ layer (this implies that this attribute is not necessarily
+ in sync with the values current in the channel subsystem).
+
+ Note: This is an I/O-subchannel specific attribute.
+Users: s390-tools, HAL
+
+What: /sys/bus/css/devices/.../driver_override
+Date: June 2019
+Contact: linux-s390@vger.kernel.org
+Description: This file allows the driver for a device to be specified. When
+ specified, only a driver with a name matching the value written
+ to driver_override will have an opportunity to bind to the
+ device. The override is specified by writing a string to the
+ driver_override file (echo vfio-ccw > driver_override) and
+ may be cleared with an empty string (echo > driver_override).
+ This returns the device to standard matching rules binding.
+ Writing to driver_override does not automatically unbind the
+ device from its current driver or make any attempt to
+ automatically load the specified driver. If no driver with a
+ matching name is currently loaded in the kernel, the device
+ will not bind to any driver. This also allows devices to
+ opt-out of driver binding using a driver_override name such as
+ "none". Only a single driver may be specified in the override,
+ there is no support for parsing delimiters.
+
+ Note that unlike the mechanism of the same name for pci, this
+ file does not allow to override basic matching rules. I.e.,
+ the driver must still match the subchannel type of the device.