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-rw-r--r--Documentation/debugging-via-ohci1394.txt17
1 files changed, 9 insertions, 8 deletions
diff --git a/Documentation/debugging-via-ohci1394.txt b/Documentation/debugging-via-ohci1394.txt
index de4804e8b396..c360d4e91b48 100644
--- a/Documentation/debugging-via-ohci1394.txt
+++ b/Documentation/debugging-via-ohci1394.txt
@@ -36,14 +36,15 @@ available (notebooks) or too slow for extensive debug information (like ACPI).
36Drivers 36Drivers
37------- 37-------
38 38
39The OHCI-1394 drivers in drivers/firewire and drivers/ieee1394 initialize 39The ohci1394 driver in drivers/ieee1394 initializes the OHCI-1394 controllers
40the OHCI-1394 controllers to a working state and can be used to enable 40to a working state and enables physical DMA by default for all remote nodes.
41physical DMA. By default you only have to load the driver, and physical 41This can be turned off by ohci1394's module parameter phys_dma=0.
42DMA access will be granted to all remote nodes, but it can be turned off 42
43when using the ohci1394 driver. 43The alternative firewire-ohci driver in drivers/firewire uses filtered physical
44 44DMA, hence is not yet suitable for remote debugging.
45Because these drivers depend on the PCI enumeration to be completed, an 45
46initialization routine which can runs pretty early (long before console_init(), 46Because ohci1394 depends on the PCI enumeration to be completed, an
47initialization routine which runs pretty early (long before console_init()
47which makes the printk buffer appear on the console can be called) was written. 48which makes the printk buffer appear on the console can be called) was written.
48 49
49To activate it, enable CONFIG_PROVIDE_OHCI1394_DMA_INIT (Kernel hacking menu: 50To activate it, enable CONFIG_PROVIDE_OHCI1394_DMA_INIT (Kernel hacking menu: