I am using dynamic attachment of devices in a device driver I've
written. It has worked on 2.2.19 (with some kernel ios mods) and 2.4.7
for some time. Now I've noticed some anomalies in the redhat 2.4.9 kernel.

If the device (in this case a 3480 tape drive) is attached at IPL, it
can be detached and attached at will and my driver's "operational"
routine gets invoked. If the device is not there at IPL and later
attached it appears the senseid CCW isn't done/fails, so the ios doesn't
know the device type, so doesn't call my operational routine. As I've
said no problems on 2.4.7, are there some new config options?


[root@pzwf1 src]# cat /proc/subchannels
Device sch.  Dev Type/Model CU  in use  PIM PAM POM LPUM CHPIDs
--------------------------------------------------------------------------
3096   0014  3480/22   3480/22  yes     FF  28  FF  08   A1D3D6BF EAEB1A1B
3093   0015            0000/00          FF  28  FF  08   A1D3D6BF EAEB1A1B

3096 above was there at IPL and can be detached and re-attached. 3093
wasn't - notice the Dev Type info etc is blank

TIA
Paul Winder

Reply via email to