CONFIG_PARPORT_PC_FIFO=y causes slow/stuttering printing through parallel port
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Confirmed
|
Medium
|
Unassigned |
Bug Description
I've done some deep testing today under following OSes (all are in the newest version):
1) CentOS 6.3
2) Fedora 17
3) openSUSE 12.2
4) Ubuntu 12.04, 12.10 and 13.04
Under all 4, there is the same ownership of /dev/lp0 and /dev/parport0 (owner root/group lp, permissions 660), BUT I have found the difference between Red Hat based systems (where the parallel printer works well) and the others (Ubuntu and openSUSE - where id doesn't work well). The output of "dmesg|grep parport" for Red Hat based is:
[ 7.522714] parport_pc 00:06: reported by Plug and Play ACPI
[ 7.522769] parport0: PC-style at 0x278 (0x678), irq 5 [PCSPP,TRISTATE]
[ 45.177790] lp0: using parport0 (interrupt-driven).
however Ubuntu and openSUSE dmesg "dmesg|grep parport" says this:
[ 21.205326] parport_pc 00:06: reported by Plug and Play ACPI
[ 21.205380] parport0: PC-style at 0x278 (0x678), irq 5, using FIFO [PCSPP,
[ 21.326415] lp0: using parport0 (interrupt-driven).
So the diffrence between those two seems to be between enabling and disabling FIFO. I've also looked at kernel configure files for Fedora 17 and Ubuntu 12.04 and I am posting the important section here:
Ubuntu 12.04 kernel configuration file (section PARPORT):
CONFIG_PARPORT=m
CONFIG_PARPORT_PC=m
CONFIG_
CONFIG_
# CONFIG_
CONFIG_
# CONFIG_PARPORT_GSC is not set
CONFIG_
CONFIG_
CONFIG_
Fedora 17 kernel configuration file (section PARPORT):
# Parallel port support
#
CONFIG_PARPORT=m
CONFIG_PARPORT_PC=m
CONFIG_
# CONFIG_
# CONFIG_
CONFIG_
CONFIG_
# CONFIG_
CONFIG_
CONFIG_
CONFIG_
I have recompiled and tested the Ubuntu kernel - printer and everything works without any problem.
Patch: Set CONFIG_
Note: this bug is already filled as #339752 but for some reason (that I can't understand) it has been marked as "WONTFIX" :(
Changed in linux (Ubuntu): | |
importance: | Undecided → Medium |
This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:
apport-collect 1152725
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.