| 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. |
