[PATCH] Documentation: correction to debugging-via-ohci1394

From: Stefan Richter
Date: Mon Feb 18 2008 - 13:40:46 EST


Rectify a factoid about firewire-ohci.

Signed-off-by: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx>
---
Ingo, I can get this to Linus via linux1394-2.6.git.

Documentation/debugging-via-ohci1394.txt | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

Index: linux-2.6.25-rc2/Documentation/debugging-via-ohci1394.txt
===================================================================
--- linux-2.6.25-rc2.orig/Documentation/debugging-via-ohci1394.txt
+++ linux-2.6.25-rc2/Documentation/debugging-via-ohci1394.txt
@@ -36,13 +36,14 @@ available (notebooks) or too slow for ex
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.
+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.

-Because these drivers depend on the PCI enumeration to be completed, an
+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 can runs pretty early (long before console_init(),
which makes the printk buffer appear on the console can be called) was written.


--
Stefan Richter
-=====-==--- --=- =--=-
http://arcgraph.de/sr/

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/