On Mon, 10 Feb 2003 11:45, Helmut Walle wrote: > Hi all, > > For the first time, I installed a parport scanner under Linux, and it > is incredibly sloooooowww!
[ ... ] > The BIOS parport setting is EPP (I also tried ECP/EPP), and dmesg > says: > > ... > parport0: PC-style at 0x378 [PCSPP,TRISTATE,EPP] > parport0: cpp_daisy: aa5500ff(38) > parport0: assign_addrs: aa5500ff(38) > parport0: cpp_daisy: aa5500ff(38) > parport0: assign_addrs: aa5500ff(38) > lp0: using parport0 (polling). > ... Here is the problem ^^^^^^^ Switch on the interrupt for the deveice and you will notice considerable performance improvement. [ ... ] > Why does parport stuff load the CPU so heavily? The data > rate is not really high enough to justify this. Or is it the > inefficiency of the polling? Indeed. -- Sincerely etc., Christopher Sawtell
