firewire: fw-ohci: add option for remote debugging

This way firewire-ohci can be used for remote debugging like ohci1394.
Version with amendment from Fri, 11 Apr 2008 00:08:08 +0200.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Bernhard Kaindl <bk@suse.de>

1 files changed, 10 insertions, 6 deletions

diff --git a/Documentation/debugging-via-ohci1394.txt b/Documentation/debugging-via-ohci1394.txt
index c360d4e91b4..59a91e5c690 100644
--- a/Documentation/debugging-via-ohci1394.txt
+++ b/Documentation/debugging-via-ohci1394.txt
@@ -41,15 +41,19 @@ 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.
+DMA by default, which is more secure but not suitable for remote debugging.
+Compile the driver with CONFIG_FIREWIRE_OHCI_REMOTE_DMA (Kernel hacking menu:
+Remote debugging over FireWire with firewire-ohci) to get unfiltered physical
+DMA.
 
-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.
+Because ohci1394 and firewire-ohci depend on the PCI enumeration to be
+completed, an initialization routine which runs pretty early has been
+implemented for x86.  This routine runs long before console_init() can be
+called, i.e. before the printk buffer appears on the console.
 
 To activate it, enable CONFIG_PROVIDE_OHCI1394_DMA_INIT (Kernel hacking menu:
-Provide code for enabling DMA over FireWire early on boot) and pass the
-parameter "ohci1394_dma=early" to the recompiled kernel on boot.
+Remote debugging over FireWire early on boot) and pass the parameter
+"ohci1394_dma=early" to the recompiled kernel on boot.
 
 Tools
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