162306a36Sopenharmony_ciWhat: /sys/bus/css/devices/.../type 262306a36Sopenharmony_ciDate: March 2008 362306a36Sopenharmony_ciContact: linux-s390@vger.kernel.org 462306a36Sopenharmony_ciDescription: Contains the subchannel type, as reported by the hardware. 562306a36Sopenharmony_ci This attribute is present for all subchannel types. 662306a36Sopenharmony_ci 762306a36Sopenharmony_ciWhat: /sys/bus/css/devices/.../modalias 862306a36Sopenharmony_ciDate: March 2008 962306a36Sopenharmony_ciContact: linux-s390@vger.kernel.org 1062306a36Sopenharmony_ciDescription: Contains the module alias as reported with uevents. 1162306a36Sopenharmony_ci It is of the format css:t<type> and present for all 1262306a36Sopenharmony_ci subchannel types. 1362306a36Sopenharmony_ci 1462306a36Sopenharmony_ciWhat: /sys/bus/css/drivers/io_subchannel/.../chpids 1562306a36Sopenharmony_ciDate: December 2002 1662306a36Sopenharmony_ciContact: linux-s390@vger.kernel.org 1762306a36Sopenharmony_ciDescription: Contains the ids of the channel paths used by this 1862306a36Sopenharmony_ci subchannel, as reported by the channel subsystem 1962306a36Sopenharmony_ci during subchannel recognition. 2062306a36Sopenharmony_ci 2162306a36Sopenharmony_ci Note: This is an I/O-subchannel specific attribute. 2262306a36Sopenharmony_ciUsers: s390-tools, HAL 2362306a36Sopenharmony_ci 2462306a36Sopenharmony_ciWhat: /sys/bus/css/drivers/io_subchannel/.../pimpampom 2562306a36Sopenharmony_ciDate: December 2002 2662306a36Sopenharmony_ciContact: linux-s390@vger.kernel.org 2762306a36Sopenharmony_ciDescription: Contains the PIM/PAM/POM values, as reported by the 2862306a36Sopenharmony_ci channel subsystem when last queried by the common I/O 2962306a36Sopenharmony_ci layer (this implies that this attribute is not necessarily 3062306a36Sopenharmony_ci in sync with the values current in the channel subsystem). 3162306a36Sopenharmony_ci 3262306a36Sopenharmony_ci Note: This is an I/O-subchannel specific attribute. 3362306a36Sopenharmony_ciUsers: s390-tools, HAL 3462306a36Sopenharmony_ci 3562306a36Sopenharmony_ciWhat: /sys/bus/css/devices/.../driver_override 3662306a36Sopenharmony_ciDate: June 2019 3762306a36Sopenharmony_ciContact: linux-s390@vger.kernel.org 3862306a36Sopenharmony_ciDescription: This file allows the driver for a device to be specified. When 3962306a36Sopenharmony_ci specified, only a driver with a name matching the value written 4062306a36Sopenharmony_ci to driver_override will have an opportunity to bind to the 4162306a36Sopenharmony_ci device. The override is specified by writing a string to the 4262306a36Sopenharmony_ci driver_override file (echo vfio-ccw > driver_override) and 4362306a36Sopenharmony_ci may be cleared with an empty string (echo > driver_override). 4462306a36Sopenharmony_ci This returns the device to standard matching rules binding. 4562306a36Sopenharmony_ci Writing to driver_override does not automatically unbind the 4662306a36Sopenharmony_ci device from its current driver or make any attempt to 4762306a36Sopenharmony_ci automatically load the specified driver. If no driver with a 4862306a36Sopenharmony_ci matching name is currently loaded in the kernel, the device 4962306a36Sopenharmony_ci will not bind to any driver. This also allows devices to 5062306a36Sopenharmony_ci opt-out of driver binding using a driver_override name such as 5162306a36Sopenharmony_ci "none". Only a single driver may be specified in the override, 5262306a36Sopenharmony_ci there is no support for parsing delimiters. 5362306a36Sopenharmony_ci 5462306a36Sopenharmony_ci Note that unlike the mechanism of the same name for pci, this 5562306a36Sopenharmony_ci file does not allow to override basic matching rules. I.e., 5662306a36Sopenharmony_ci the driver must still match the subchannel type of the device. 57