Bugs item #1951768, was opened at 2008-04-25 18:11
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Category: None
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Jan Van Gilsen (janvangilsen)
Assigned to: Nobody/Anonymous (nobody)
Summary: parport: in-mode

Initial Comment:
When using the parallel port data bits as input, bit 5 (or 7) of the control 
register is set. This setting is done in the write_port function.
If a port is only used as inputdevice, and write_port isn't added to a thread, 
the data inputs won't work. (not tested)

This control bit should be set at least once outside the write_port function, 
if the data bits are configured as inputs.

---------------------------

"A few ports use bit 7 instead of bit 5 as direction control. To ensure 
compatibility with al ports, software can toggle both bits 5 and 7 to set 
direction" - The Parallel Port Complete - Jan Axelson (ISBN 096508191-5) pg. 24

atm only bit 5 is set: (hal_parport.c)
/* prepare to build control port byte, with direction bit set */
outdata = 0x20;

this could be changed into:

outdata = 0xA0;


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