Bug 56721 - Parport driver uses FIFO even if DMA is disabled in BIOS
Summary: Parport driver uses FIFO even if DMA is disabled in BIOS
Status: NEW
Alias: None
Product: Drivers
Classification: Unclassified
Component: Parallel (show other bugs)
Hardware: All Linux
: P1 high
Assignee: drivers_parallel
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2013-04-17 11:09 UTC by Pavel Šefránek
Modified: 2016-02-17 18:22 UTC (History)
1 user (show)

See Also:
Kernel Version: 3.8.0.18.34
Subsystem:
Regression: No
Bisected commit-id:

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Description Pavel Šefránek 2013-04-17 11:09:04 UTC 
If CONFIG_PARPORT_PC_FIFO is set to "y" parport driver is using FIFO everytime despite DMA is disabled in BIOS. This causes slow/stuttering printing through parallel port. 

When I turn DMA on or set CONFIG_PARPORT_PC_FIFO to "n" printer works as expected.
Comment 1 Pavel Šefránek 2013-05-31 09:04:36 UTC 
Related Ubuntu bug with more info: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/339752
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