Re: firewire-ohci fails to initialize Texas Instruments XIO2213A/B/XIO2221 based controller on realtime kernels [5.4.91-rt50, 5.10.8-rt24]

From: Takashi Sakamoto <o-takashi@sakamocchi.jp>
To: David Runge <dave@sleepmap.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Kristian Hoegsberg <krh@bitplanet.net>,
	linux1394-devel@lists.sourceforge.net,
	linux-rt-users@vger.kernel.org,
	"Ahmed S. Darwish" <a.darwish@linutronix.de>
Subject: Re: firewire-ohci fails to initialize Texas Instruments XIO2213A/B/XIO2221 based controller on realtime kernels [5.4.91-rt50, 5.10.8-rt24]
Date: Thu, 9 Sep 2021 09:46:06 +0900	[thread overview]
Message-ID: <YTlZTvb6B3O2as+q@workstation> (raw)
In-Reply-To: <YTjzKftQmFtPLYUR@hmbx>

On Wed, Sep 08, 2021 at 07:30:14PM +0200, David Runge wrote:
> I am using '-1' (all) in the 2nd link in my previous mail. It appears to
> not show a different output in the kernel logs from when I set it to '5'
> though. There seems to be something wrong...
> I'm adding the options in a .conf file below /etc/modprobe.d/, e.g.:
> 
> ```
> options firewire-ohci debug=5
> ```
> 
> The only output I get from that is:
> 
> ```
> firewire_ohci 0000:05:00.0: enabling device (0000 -> 0002)
> firewire_ohci 0000:05:00.0: added OHCI v1.10 device as card 0, 8 IR + 8 IT contexts, quirks 0x2
> firewire_core 0000:05:00.0: created device fw0: GUID 7856341278563412, S800
> firewire_ohci 0000:05:00.0: isochronous cycle inconsistent
> firewire_core 0000:05:00.0: created device fw1: GUID 000a3500ada83262, S400
> firewire_core 0000:05:00.0: phy config: new root=ffc0, gap_count=5
> ```

Before printing 'created device fw1', Linux FireWire subsystem already
initiates asynchronous transactions to retrieve content of configuration
ROM located in 0x'ffff'f000'0400 of node address space. If you can see
no transaction record but see the print, it means to fail configuration
of the parameter of firewire-ohci module.

I think your system uses initramfs. Any node for storage function in
IEEE 1394 bus is available as initial boot disk, thus it's reasonable
that the designer of your initramfs puts firewire-ohci/firewire-core
modules into it. In the case, we can not configure module by
'/etc/modprobe.d/*' since the modules are already loaded before mounting
root file system.

I think the design of initramfs differs depending on distribution, thus
you need to find instruction for the way to configure module parameter
by yourself.

Instead, I suggest you to configure the module via sysfs after booting,
like:

```
# echo 5 > /sys/module/firewire_ohci/parameters/debug
```

Then retry detection of node for your Fireface 800. When turning off the
debug print, write 0 to the node of sysfs.

Regards

Takashi Sakamoto