[lcd4linux] Problems with Parport and HD44780 driver

[Stefan U. H. <st...@he...>]

Hi there,

I just migrated to a new server and also moved the lcd4linux display to
the new box.
As with the old server, I added a multi-io card to get the legacy
parport for lcd4linux.

It's a Delock PCIx Parport & 2x Serial card (in total the machine has
two of those). Here's the output from lspci -v:

    07:00.2 Parallel controller: MosChip Semiconductor Technology Ltd.
    PCIe 9912 Multi-I/O Controller (prog-if 03 [IEEE1284])
        Subsystem: Device a000:2000
        Flags: bus master, fast devsel, latency 0, IRQ 17
        I/O ports at 4010 [size=8]
        I/O ports at 4000 [size=8]
        Memory at b1510000 (32-bit, non-prefetchable) [size=4K]
        Memory at b1500000 (32-bit, non-prefetchable) [size=4K]
        Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
        Capabilities: [78] Power Management version 3
        Capabilities: [80] Express Legacy Endpoint, MSI 00
        Capabilities: [100] Advanced Error Reporting
        Kernel driver in use: parport_serial

The lcd4linux.conf says regarding the display:

    Display HD44780-generic {
        Driver 'HD44780'
        Model 'generic'
        Port '/dev/parport1'
        Size '20x4'
        asc255bug 0
        Icons 2
        GPOs 0
        Wire {
            RW      'GND'
            RS      'AUTOFD'
            ENABLE  'STROBE'
            ENABLE2 'GND'
            GPO     'INIT'
            POWER   'GND'
        }
        Timing {
            fuzz '175'
        }
    }

But when I start lcd4linux I get after a while (but mostly right at
startup) the following error:

    HD44780: ioctl(/dev/parport1, PPCLAIM) failed: 4 Interrupted system call
    HD44780: could not initialize parallel port!
    HD44780: start display failed!
    Error initializing driver HD44780: Exit!

Does this sound like a timing issue?

I got no clue about the lowlevel timings. I now just took the example
from the website and replaced the old fuzz-setting:

     Timing {
        CY    1000  
        PW     450  
        AS     140  
        AH      20  
        INIT1 4100
        INIT2  100
        EXEC    80
        WRCG   120
        CLEAR 2250
        HOME  2250
        ONOFF 2250
        GPO_ST  20
        GPO_PW 230
        POWER  500
     }

For the moment, this seems to work. However, I'd appreciate, if someone
could drop me a line or two about this, because I'd like to undstand
what I'm doing and where to tweak, If I run into trouble again.

Thanks a lot in advance.

Stefan.

-- 
Stefan U. Hegner
         <st...@he...>
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D-32584 Löhne --- good ole Germany
internet: http://www.hegner-web.de
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