On Thu, Aug 16, 2001 at 12:52:16PM -0400, Dave Strauss wrote:
> First problem: once the port is in ECP mode, any call to
> lp_wait_ready() will fail because the call to lp_check_status() will
> be wrong because the status lines mean different things in ECP mode.
> I've gotten around it by getting out of lp_wait_ready() immediately
> if the device is not in compatibility mode, but I'm not convinced this
> is the correct thing to do. Perhaps lp_check_status() should be
> changed instead.
Yeah, tricky. I guess your solution is about the best though.
> I've gotten around this in the patch below by always reverting to
> compatibility mode when the write is completed, but again I'm not
> sure this is the correct thing.
It is. We shouldn't ever release the port when it isn't ready for use
by some other driver (i.e. not in compatibility mode).
> Third problem: the data transfer rate is still very slow. I'm
> expecting upwards or 400 Kbytes/sec but and getting only about 50
> Kbytes/sec. I'm not why this is so.
Philip found this too I think. Is CONFIG_PARPORT_PC_FIFO enabled in
your kernel? Does 'dmesg' say that it's using DMA?
> Fourth problem: I'm getting garbage in the data stream. At this point
> I haven't been able to characterize it very well beyong the fact that
> the data reaching the printer is incorrect. I'm not sure if I'm
> getting extra characters, dropped characters, garbled characters, or
> all three.
That's not good. :-/
Tim.
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This archive was generated by hypermail 2b29 : Thu Aug 16 2001 - 13:12:55 EDT