On 26.10.2016 22:53, Philipp Kern wrote: > On 10/26/2016 05:13 PM, Dimitri John Ledkov wrote: >> Currently s390-netdevice in the code supports following >> networktypes: * qeth * ctc * iucv * virtio >> >> virtio is, in fact, a no-op. > > Yup. > >> iucv refers to "IUCV network device" which has been deprecated >> at least since October 2005 (linux v2.6+) > > I guess IUCV is only deprecated for networking, not for console > access, right? I would not mind dropping it then. > >> ctc refers to channel-to-channel devices which has also been >> deprecated at least since October 2005 (linux v2.6+) > > CTC is used by default by Hercules. I suppose it can also do qeth > now? Or maybe that's just in a fork? Last I checked it still > worked, as well. > >> The migration path from above to is onto Hipersockets or QDIO. >> Both migration paths are handled on the linux side by the qeth >> kernel module as fas as I understand. >> >> Hence, the only option of the 4 that may do anything is qeth, if >> there are any qeth devices detected that need activation. >> >> Furthermore, I'm not sure if iucv network device works correctly >> - confirm_iucv function returns WANT_ERROR, unless after >> activating iucv one must continue with the ctc code path. >> >> Imho, we should simply skip the whole d-i module if there are no >> qeth devices to activate. If there are any qeth devices to >> activate, display multi select question of the qeth devices to >> activate. Multi-select question, such that continue without >> selecting any is a valid option (for example if one wants to >> install using the PCIe interfaces). > > I very much sympathize with this idea in general. If we can also > detect if CTC devices are on the bus, only showing the prompt if > devices can be found would be useful. Did the kernel start off not > offering all devices in sysfs because LPARs can have a huge amount > of them? Or did it always rely on blacklisting in this case? I > suppose that the original reason was that you actually had to enter > device numbers because it couldn't probe, but then on the other > hand the selection for qeth was shown for a long time now. Whether (and which) CCW devices are probed and exposed via sysfs is controlled by the cio_ignore kernel parameter, actually black and white listing at the same time. And the reason to add this was that LPARs can have really many devices. The last time I looked the installer modules were not equipped to deal with cio_ignore and the installer image didn't utilize the cio_ignore parameter, so a Debian installer will see all CCW devices. > > Kind regards and thanks Philipp Kern >
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