* [PATCH] Documentation: correction to debugging-via-ohci1394
@ 2008-02-18 18:40 Stefan Richter
2008-02-18 19:09 ` Ingo Molnar
0 siblings, 1 reply; 2+ messages in thread
From: Stefan Richter @ 2008-02-18 18:40 UTC (permalink / raw)
To: linux-kernel; +Cc: linux1394-devel, Bernhard Kaindl, Ingo Molnar
Rectify a factoid about firewire-ohci.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
---
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/
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] Documentation: correction to debugging-via-ohci1394
2008-02-18 18:40 [PATCH] Documentation: correction to debugging-via-ohci1394 Stefan Richter
@ 2008-02-18 19:09 ` Ingo Molnar
0 siblings, 0 replies; 2+ messages in thread
From: Ingo Molnar @ 2008-02-18 19:09 UTC (permalink / raw)
To: Stefan Richter; +Cc: linux-kernel, linux1394-devel, Bernhard Kaindl
* Stefan Richter <stefanr@s5r6.in-berlin.de> wrote:
> Rectify a factoid about firewire-ohci.
>
> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
> ---
> Ingo, I can get this to Linus via linux1394-2.6.git.
please do, thanks.
Acked-by: Ingo Molnar <mingo@elte.hu>
Ingo
^ permalink raw reply [flat|nested] 2+ messages in thread
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