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authorStefan Richter <stefanr@s5r6.in-berlin.de>2008-02-18 21:38:35 +0100
committerStefan Richter <stefanr@s5r6.in-berlin.de>2008-02-19 19:57:24 +0100
commit09d7328e62e3b4cefe4bf3eeeeacb54f62a7ae5c (patch)
treea5997316a4b9a43af9d1aab8b1c8c164ab240a8d /Documentation/debugging-via-ohci1394.txt
parentef774c16a744f130f27c654bf9c4806e767fc773 (diff)
downloadlinux-09d7328e62e3b4cefe4bf3eeeeacb54f62a7ae5c.tar.bz2
Documentation: correction to debugging-via-ohci1394
Rectify a factoid about firewire-ohci. Acked-by: Ingo Molnar <mingo@elte.hu> Also fix a typo spotted by Bernhard Kaindl. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'Documentation/debugging-via-ohci1394.txt')
-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).
Drivers
-------
-The OHCI-1394 drivers in drivers/firewire and drivers/ieee1394 initialize
-the OHCI-1394 controllers to a working state and can be used to enable
-physical DMA. By default you only have to load the driver, and physical
-DMA access will be granted to all remote nodes, but it can be turned off
-when using the ohci1394 driver.
-
-Because these drivers depend on the PCI enumeration to be completed, an
-initialization routine which can runs pretty early (long before console_init(),
+The ohci1394 driver in drivers/ieee1394 initializes the OHCI-1394 controllers
+to a working state and enables physical DMA by default for all remote nodes.
+This can be turned off by ohci1394's module parameter phys_dma=0.
+
+The alternative firewire-ohci driver in drivers/firewire uses filtered physical
+DMA, hence is not yet suitable for remote debugging.
+
+Because ohci1394 depends on the PCI enumeration to be completed, an
+initialization routine which runs pretty early (long before console_init()
which makes the printk buffer appear on the console can be called) was written.
To activate it, enable CONFIG_PROVIDE_OHCI1394_DMA_INIT (Kernel hacking menu: