Re: parallel port *slow*

From: Palle Girgensohn <girgen_at_pingpong.net>
Date: Thu, 15 Jul 2004 23:07:11 +0200
Only, the flags don't work, nothing seems to happen?

$ kenv | grep  ppc
hint.ppc.0.at="isa"
hint.ppc.0.flags="0xc"
hint.ppc.0.irq="7"
$ dmesg | grep ppc
ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0
ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode
ppc0: FIFO with 16/16/16 bytes threshold
ppbus0: <Parallel port bus> on ppc0


--On torsdag, juli 15, 2004 19.00.18 +0100 Antony T Curtis 
<antony.t.curtis_at_ntlworld.com> wrote:

> On Thu, 2004-07-15 at 16:42, Palle Girgensohn wrote:
>> Hi!
>>
>>
>> For a while now my parallel port (with printer hooked up) has been
>> *really  SLOW*. Takes several minutes to print a single very simple page.
>>
>> Any idea how to debug or what to try/fix?
>>
>> All I see in the log is:
>
> <snip>
>
>> ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0
>> ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode
>> ppc0: FIFO with 16/16/16 bytes threshold
>
> if you do a "man ppc" there are flags settable on the ppc device.
> If you set the flags so that it is in ECP mode, it will be much faster.
> Even EPP mode works faster.
>
> IIRC Compatible mode uses an interrupt for every character. EPP can
> handle a burst of characters while ECP uses DMA so can transfer a large
> block per interrupt.
>
> --
> Antony T Curtis <antony.t.curtis_at_ntlworld.com>
>
Received on Thu Jul 15 2004 - 19:07:12 UTC

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