diff options
| author | Ralf Baechle <ralf@linux-mips.org> | 2001-01-10 17:17:53 +0000 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2001-01-10 17:17:53 +0000 |
| commit | b2ad5f821b1381492d792ca10b1eb7a107b48f14 (patch) | |
| tree | 954a648692e7da983db1d2470953705f6a729264 /Documentation/parport.txt | |
| parent | c9c06167e7933d93a6e396174c68abf242294abb (diff) | |
Merge with Linux 2.4.0-prerelease. Big Makefile rewrite, test your
Makefiles.
Diffstat (limited to 'Documentation/parport.txt')
| -rw-r--r-- | Documentation/parport.txt | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/Documentation/parport.txt b/Documentation/parport.txt index 59e75b5fa..27c6d1c40 100644 --- a/Documentation/parport.txt +++ b/Documentation/parport.txt @@ -219,6 +219,46 @@ Also: * IRQ autoprobing works only for a few port types at the moment. +Reporting printer problems with parport +======================================= + +If you are having problems printing, please go through these steps to +try to narrow down where the problem area is. + +When reporting problems with parport, really you need to give all of +the messages that parport_pc spits out when it initialises. There are +several code paths: + +o polling +o interrupt-driven, protocol in software +o interrupt-driven, protocol in hardware using PIO +o interrupt-driven, protocol in hardware using DMA + +The kernel messages that parport_pc logs give an indication of which +code path is being used. (They could be a lot better actually..) + +For normal printer protocol, having IEEE 1284 modes enabled or not +should not make a difference. + +To turn off the 'protocol in hardware' code paths, disable +CONFIG_PARPORT_PC_FIFO. Note that when they are enabled they are not +necessarily _used_; it depends on whether the hardware is available, +enabled by the BIOS, and detected by the driver. + +So, to start with, disable CONFIG_PARPORT_PC_FIFO, and load parport_pc +with 'irq=none'. See if printing works then. It really should, +because this is the simplest code path. + +If that works fine, try with 'io=0x378 irq=7' (adjust for your +hardware), to make it use interrupt-driven in-software protocol. + +If _that_ works fine, then one of the hardware modes isn't working +right. Enable CONFIG_PARPORT_PC_FIFO (no, it isn't a module option, +and yes, it should be), set the port to ECP mode in the BIOS and note +the DMA channel, and try with: + + io=0x378 irq=7 dma=none (for PIO) + io=0x378 irq=7 dma=3 (for DMA) -- Philip.Blundell@pobox.com tim@cyberelk.demon.co.uk |