On Thu, Aug 30, 2001 at 10:45:51AM -0400, Dave Strauss wrote:
> On Thu, 30 Aug 2001 15:43:23 +0100, Philip Blundell <pb@nexus.co.uk> wrote:
> >
> > >no longer does the "keep-alive" thing. It downloads a bunch of data,
> > >writes the flash, downloads a bunch of data, write the flash, and so
> > >on. It can be almost a minute between downloads in some cases.
> >
> > Ah, I see.
> >
> > Well, in theory these timeouts should be non-fatal. The code in
> > parport_pc goes to some trouble to make sure it knows how much data
> > was left in the FIFO when the timeout occurred, in order to make
> > sure that none is lost. But it's entirely possible that bugs are
> > lurking, for example if it's misdetecting the depth of the FIFO at
> > initialisation.
>
> Yes, I had a quick look at the timeout recovery code, but didn't see
> anything obvious. :-(
I think, that parport code isn't to bad :)
Recently I did some graphics 1200dpi printings on my HP LJ2100. They were
horrible long ( 1-2 minutes per page). In longs were some messages :)
Aug 24 15:40:31 mirek kernel: DMA write timed out
Aug 24 15:42:00 mirek kernel: DMA write timed out
Aug 24 15:43:29 mirek kernel: DMA write timed out
Aug 24 15:45:53 mirek kernel: parport0: FIFO is stuck
Aug 24 15:45:53 mirek kernel: parport0: BUSY timeout (1) in compat_write_block_pio
Aug 24 15:46:42 mirek kernel: DMA write timed out
Aug 24 15:47:13 mirek kernel: parport0: BUSY timeout (1) in compat_write_block_pio
Aug 24 15:47:31 mirek kernel: DMA write timed out
Aug 24 15:48:17 mirek kernel: parport0: FIFO is stuck
The PCL files have size only about 200-800 KB/page. Mesages like above
doesn't appear with files size about 200KB, but files 600-800KB gave mostly
one "DMA write timed out" message.
I tried to find solution. But I thing it is only printer problem. In tests
dd if=/dev/zero of=/dev/lp0
I got troughput about 370 KB/s (Pentium 200, motherboard Asus T2P4 with SMC
FDC37C669QF i/o chip). Not too bad :)
In pure DOS (6.22) graphics printing (copy /b x.lj prn) speed is about 10%
higher then in linux.
Other side my parport tests, I checked again my old ZIP100 (ppa). Currently
(kernel 2.4.8-ac4) hdparm gives only 140 kB/s :( It was once an experimental
ppa (as I remeber I used it with kernel 2.0.x) with some tuning parameters
that gave ZIP100 usable with about 650 kB/s (same computer) :(
Mirek
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