Documentation/: update FireWire debugging documentation

The old firewire stack is long dead now and a new version firescope has
been released with support for current kernels.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Cc: Rob Landley <rob@landley.net>
Cc: Justin P. Mattock <justinmattock@gmail.com>
Cc: Bernhard Kaindl <bk@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This commit is contained in:
Lubomir Rintel 2013-12-22 11:31:41 +01:00 committed by Stefan Richter
parent 7e22e91102
commit a9954ce769
2 changed files with 10 additions and 16 deletions

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@ -36,17 +36,13 @@ available (notebooks) or too slow for extensive debug information (like ACPI).
Drivers
-------
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
The firewire-ohci driver in drivers/firewire uses filtered physical
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 and firewire-ohci depend on the PCI enumeration to be
Because the firewire-ohci driver depends 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.
@ -64,7 +60,7 @@ be used to view the printk buffer of a remote machine, even with live update.
Bernhard Kaindl enhanced firescope to support accessing 64-bit machines
from 32-bit firescope and vice versa:
- http://halobates.de/firewire/firescope-0.2.2.tar.bz2
- http://v3.sk/~lkundrak/firescope/
and he implemented fast system dump (alpha version - read README.txt):
- http://halobates.de/firewire/firedump-0.1.tar.bz2
@ -92,11 +88,11 @@ Step-by-step instructions for using firescope with early OHCI initialization:
1) Verify that your hardware is supported:
Load the ohci1394 or the fw-ohci module and check your kernel logs.
Load the firewire-ohci module and check your kernel logs.
You should see a line similar to
ohci1394: fw-host0: OHCI-1394 1.1 (PCI): IRQ=[18] MMIO=[fe9ff800-fe9fffff]
... Max Packet=[2048] IR/IT contexts=[4/8]
firewire_ohci 0000:15:00.1: added OHCI v1.0 device as card 2, 4 IR + 4 IT
... contexts, quirks 0x11
when loading the driver. If you have no supported controller, many PCI,
CardBus and even some Express cards which are fully compliant to OHCI-1394
@ -113,20 +109,18 @@ Step-by-step instructions for using firescope with early OHCI initialization:
If an driver is running on both machines you should see a line like
ieee1394: Node added: ID:BUS[0-01:1023] GUID[0090270001b84bba]
firewire_core 0000:15:00.1: created device fw1: GUID 00061b0020105917, S400
on both machines in the kernel log when the cable is plugged in
and connects the two machines.
3) Test physical DMA using firescope:
On the debug host,
- load the raw1394 module,
- make sure that /dev/raw1394 is accessible,
On the debug host, make sure that /dev/fw* is accessible,
then start firescope:
$ firescope
Port 0 (ohci1394) opened, 2 nodes detected
Port 0 (/dev/fw1) opened, 2 nodes detected
FireScope
---------

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@ -172,7 +172,7 @@ you can boot the kernel with the 'no_console_suspend' parameter and try to log
kernel messages using the serial console. This may provide you with some
information about the reasons of the suspend (resume) failure. Alternatively,
it may be possible to use a FireWire port for debugging with firescope
(ftp://ftp.firstfloor.org/pub/ak/firescope/). On x86 it is also possible to
(http://v3.sk/~lkundrak/firescope/). On x86 it is also possible to
use the PM_TRACE mechanism documented in Documentation/power/s2ram.txt .
2. Testing suspend to RAM (STR)