** Description changed: Ubuntu 12.04 64 bit (also 32 bit is affected) Zebra LP 2844-Z USB printer - connected with a generic "raw queue" driver. usblp0 appears to disconnect after every print job and then automatically reconnect after 8 seconds. The next job to the printer won't print until it is reconnected. This is a problem for us in a high volume printing scenario. Here are messages from syslog: May 17 16:47:17 mlcx500 kernel: [25464.991868] usblp0: removed May 17 16:47:25 mlcx500 kernel: [25473.131745] usblp0: USB Bidirectional printer dev 5 if 0 alt 0 proto 2 vid 0x0A5F pid 0x0027 May 17 16:47:25 mlcx500 udev-configure-printer: add /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/usb/lp0 May 17 16:47:25 mlcx500 udev-configure-printer: device devpath is /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2 May 17 16:47:25 mlcx500 udev-configure-printer: Device already handled Note the 8 second pause between the first and second messages. Not sure where the disconnect is coming from. It doesn't appear to be hardware related as I have the problem with various combinations of printer and computer. + [IMPACT] + + On some printers it can happen that with Precise's new libusb-based USB + CUPS backend there is a small delay of around 8 seconds after each job. + In environments where printers are continuously printing small jobs (~1 + page each) this is a serious impact on printing performance. + + The USB backend in the proposed package has a configurable option to + turn off the bi-directional operation of the backend (sending print data + and also reading answers of the printer). With uni-directional printing + (only sending print data) the delay disappears. + + Uni-directional printing can be set manually. We will give instructions + in the Release Notes of 12.04.1. + + [TESTCASE] + + Unfortunately, for reproducing this bug one needs the actual printer. + + Connect a printer with the problem to the USB port of the computer. + + With current Precise you get the mentioned 8-second delay after each job + when you print several jobs one after the other. If you install the + proposed package you can suppress bi-directional printing via + + lpadmin -p <queue name> -o usb-unidir-default=true + + Now the jobs get printed directly one after the other. + + [Regression Potential] + + The patch looks perhaps more dramatic than it is. This is because + several code sections are put into "if" blocks, indenting all the + (unchanged) code lines. This especially happens because now we suppress + using the back channel for selected printers (and also printers which + claim to be uni-directional only). + + The code was developed in several steps and uploaded step-by-step to my + PPA. There the reporters of the bugs covered by this SRU and some + additional bugs (bug 902535, bug 995111) tested it intensively. They did + not hit any regressions compared to stock Precise or the first CUPS SRU. + + The code is also applied to the CUPS package in Quantal and this also + did not cause any regression bug report yet. + + I have tested the code on four HP printers (HP LaserJet 3390, HP Color + LaserJet CM3530 MFP, HP PhotoSmart C8100, HP PhotoSmart C5200, all on + direct USB) and one Epson printer (Epson Stylus Photo 880, both direct + USB and parallel with Prolific USB -> Parallel adaptor) and all work + fine, no regressions. + + ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: cups 1.5.2-9ubuntu1 ProcVersionSignature: Ubuntu 3.2.0-24.37-generic 3.2.14 Uname: Linux 3.2.0-24-generic x86_64 NonfreeKernelModules: nvidia ApportVersion: 2.0.1-0ubuntu7 Architecture: amd64 Date: Thu May 17 17:47:22 2012 InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425) Lpstat: - device for Officejet-6300-series: dnssd://Officejet%206300%20series%20%5B75F808%5D._pdl-datastream._tcp.local/ - device for z6: usb://Zebra%20Technologies/ZTC%20LP2844-Z-200dpi?serial=46J083000010 + device for Officejet-6300-series: dnssd://Officejet%206300%20series%20%5B75F808%5D._pdl-datastream._tcp.local/ + device for z6: usb://Zebra%20Technologies/ZTC%20LP2844-Z-200dpi?serial=46J083000010 MachineType: Dell Inc. Precision M6500 Papersize: letter PccardctlIdent: - Socket 0: - no product info available + Socket 0: + no product info available PccardctlStatus: - Socket 0: - no card + Socket 0: + no card PpdFiles: Officejet-6300-series: HP Officejet 6300 Series, hpcups 3.12.2 ProcEnviron: - TERM=xterm - PATH=(custom, no user) - LANG=en_US.UTF-8 - SHELL=/bin/bash + TERM=xterm + PATH=(custom, no user) + LANG=en_US.UTF-8 + SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-24-generic root=UUID=c519e5fe-c1ce-42e5-a875-c395070a15ab ro quiet splash vt.handoff=7 SourcePackage: cups UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 06/07/2010 dmi.bios.vendor: Dell Inc. dmi.bios.version: A04 dmi.board.vendor: Dell Inc. dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvrA04:bd06/07/2010:svnDellInc.:pnPrecisionM6500:pvr:rvnDellInc.:rn:rvr:cvnDellInc.:ct8:cvr: dmi.product.name: Precision M6500 dmi.sys.vendor: Dell Inc. mtime.conffile..etc.cups.cupsd.conf: 2012-05-17T17:39:15.321368
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1001028 Title: Delay after every print job on USB To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cups/+bug/1001028/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
