| 1 | What: /sys/bus/css/devices/.../type |
| 2 | Date: March 2008 |
| 3 | Contact: [email protected] |
| 4 | Description: Contains the subchannel type, as reported by the hardware. |
| 5 | This attribute is present for all subchannel types. |
| 6 | |
| 7 | What: /sys/bus/css/devices/.../modalias |
| 8 | Date: March 2008 |
| 9 | Contact: [email protected] |
| 10 | Description: Contains the module alias as reported with uevents. |
| 11 | It is of the format css:t<type> and present for all |
| 12 | subchannel types. |
| 13 | |
| 14 | What: /sys/bus/css/drivers/io_subchannel/.../chpids |
| 15 | Date: December 2002 |
| 16 | Contact: [email protected] |
| 17 | Description: Contains the ids of the channel paths used by this |
| 18 | subchannel, as reported by the channel subsystem |
| 19 | during subchannel recognition. |
| 20 | |
| 21 | Note: This is an I/O-subchannel specific attribute. |
| 22 | Users: s390-tools, HAL |
| 23 | |
| 24 | What: /sys/bus/css/drivers/io_subchannel/.../pimpampom |
| 25 | Date: December 2002 |
| 26 | Contact: [email protected] |
| 27 | Description: Contains the PIM/PAM/POM values, as reported by the |
| 28 | channel subsystem when last queried by the common I/O |
| 29 | layer (this implies that this attribute is not necessarily |
| 30 | in sync with the values current in the channel subsystem). |
| 31 | |
| 32 | Note: This is an I/O-subchannel specific attribute. |
| 33 | Users: s390-tools, HAL |
| 34 | |
| 35 | What: /sys/bus/css/devices/.../driver_override |
| 36 | Date: June 2019 |
| 37 | Contact: [email protected] |
| 38 | Description: This file allows the driver for a device to be specified. When |
| 39 | specified, only a driver with a name matching the value written |
| 40 | to driver_override will have an opportunity to bind to the |
| 41 | device. The override is specified by writing a string to the |
| 42 | driver_override file (echo vfio-ccw > driver_override) and |
| 43 | may be cleared with an empty string (echo > driver_override). |
| 44 | This returns the device to standard matching rules binding. |
| 45 | Writing to driver_override does not automatically unbind the |
| 46 | device from its current driver or make any attempt to |
| 47 | automatically load the specified driver. If no driver with a |
| 48 | matching name is currently loaded in the kernel, the device |
| 49 | will not bind to any driver. This also allows devices to |
| 50 | opt-out of driver binding using a driver_override name such as |
| 51 | "none". Only a single driver may be specified in the override, |
| 52 | there is no support for parsing delimiters. |
| 53 | |
| 54 | Note that unlike the mechanism of the same name for pci, this |
| 55 | file does not allow to override basic matching rules. I.e., |
| 56 | the driver must still match the subchannel type of the device. |