On Thu 30 Sep 2021 at 08:57:13 +0200, Giacomo Mulas wrote: > On Wed, 29 Sep 2021, Debian Bug Tracking System wrote: > > > #995322: ipp-usb: prevents hp-toolbox and libsane-hpaio from working > > > > It has been closed by Brian Potkin <claremont...@gmail.com>. > > > > Much of your time would have been saved by reading the Release > > Notes. Please submit another report if you feel the documentation > > is inadequate. > > Indeed it is. As I said, ipp-usb got automatically installed upon upgrading > to bullseye, together with tons of other packages. The only piece of > information I was shown was the NEWS.Debian file of ipp-usb (together with > dozens of other messages). The only thing it says is "Existing or newly > created queues on a USB connection for IPP-over-USB > capable devices using vendor drivers will not work while the ipp-usb > service is activated and managing the connection." > This is only about printing, no clue about other functions of the same > device.
ipp-usb is a recommended package for cups-daemon and libsane1. That the NEWS file does not mention scanning is a fair point. Does the addotion of a third paragrapgh allay your concern? If so, I woud suggest subnitting a report against ipp-usb. The change is not extensive and could make it into a bullseye point release. ------------------------------------------------------------------- ipp-usb uses the IPP-over-USB protocol to allow the setting up of a driverless print queue for most USB connected modern multi-function and a few modern USB-only devices. The default is to auto-setup the queue with cups-browsed. Existing or newly created queues on a USB connection for IPP-over-USB capable devices using vendor drivers will not work while the ipp-usb service is activated and managing the connection. The same protocol also allows discovery of modern scanner devices via libsane1. Oncve again, vendor drivers will not work while the ipp-usb service is activated and managing the connection. Details are at https://wiki.debian.org/CUPSDriverlessPrinting ------------------------------------------------------------------- BTW, Xsane should have given you two backends to access. hpaio will not work bit escl should. I guess that was not the case. That is a bug in escl and why the wiko points to sane-airscan as an alternative. > Only _after_ discovering that ipp-usb was preventing xsane to > connect to the scanner I looked at > https://wiki.debian.org/CUPSDriverlessPrinting > and found this warning in there: > "Note that IPP-over-USB reserves the USB interface connection with the > printer/scanner exclusively for itself and communication with a > printer/scanner device by software that does not operate using the > IPP-over-USB protocol becomes impossible while ipp-usb is running. This is > a consequence of the design of USB communication. It is not a bug in > ipp-usb. (omissis) Communicating with a USB connected scanner via classic > SANE backends such as libsane-hpaio, sane-pixma or sane-epson2 also becomes > impossible with the ipp-usb daemon active and running." > > Had I seen _this_ warning in the release notes, _then_ this would have got > some alarm ringing and I would not have wasted hours tracking this. > > So, please: do include the above warning, in full, in the release notes of > ipp-usb. I think that duplicating in the Release Notes what is on the wiki is not the way to go, but you could submit a bug against the release-notes pseudo-package. > Also, it would be helpful to add at least a "Suggests" to install also the > package sane-airscan along with it, since this will restore most > multifunction devices to properly work again as scanners when ipp-usb is > running. That would be for the libsane1 maintainer to consider. Note that he has already declined to make sane-airscan a Recommends: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=971658 Cheers, Brian.
