of those devices is uniquely defined by a so called subchannel by the ESA/390
channel subsystem. While the subchannel numbers are system generated, each
subchannel also takes a user defined attribute, the so called device number.
-Both subchannel number and device number cannot exceed 65535. During driverfs
+Both subchannel number and device number cannot exceed 65535. During sysfs
initialisation, the information about control unit type and device types that
imply specific I/O commands (channel command words - CCWs) in order to operate
the device are gathered. Device drivers can retrieve this set of hardware
timeout value
-EIO: the common I/O layer terminated the request due to an error state
-If the concurrent sense flag in the extended status word in the irb is set, the
-field irb->scsw.count describes the number of device specific sense bytes
-available in the extended control word irb->scsw.ecw[0]. No device sensing by
-the device driver itself is required.
+If the concurrent sense flag in the extended status word (esw) in the irb is
+set, the field erw.scnt in the esw describes the number of device specific
+sense bytes available in the extended control word irb->scsw.ecw[]. No device
+sensing by the device driver itself is required.
The device interrupt handler can use the following definitions to investigate
the primary unit check source coded in sense byte 0 :