I try to connect a HP Laserjet 6P with Centronics connection to an Acer Veriton M4640G on openSUSE 13.2 32 bit. The parallel port is provided by a
03:00.0 Communication controller: MosChip Semiconductor Technology Ltd. PCI 9815 Multi-I/O Controller (rev 01)
Subsystem: LSI Logic / Symbios Logic 2P0S (2 port parallel adaptor)
Flags: medium devsel, IRQ 18
I/O ports at d050 [size=8]
I/O ports at d040 [size=8]
I/O ports at d030 [size=8]
I/O ports at d020 [size=8]
I/O ports at d010 [size=8]
I/O ports at d000 [size=16]
Kernel modules: parport_pc
PCI card.
Yast correctly finds and initializes the printer, printing of some characters works, longer texts or graphics print garbage.
Exactly the same happens with a HP Laserjet 4MP.

Also the same happens with the same printers on a second computer with Leap 42.1 and two other different PCI-Express parport cards with different chips.
The Windows7 64 bit installation on this second computer worked with the same printers and both PCI-Express cards IIRC.

A third computer with the older openSUSE 13.1 32 bit worked OK with the "LSI Logic / Symbios Logic 2P0S" card, other cards not tested, sadly that computer died. :-(

Is it possible that newer kernels have problems with the parallel port, timing/handshake maybe?

Any help very appreciated, thanks,