[ANNOUNCE] Thunderbolt/USB4 debugging tools

[ANNOUNCE] Thunderbolt/USB4 debugging tools

[Mika Westerberg]

Hi all,

This is mostly for the folks developing and testing Thunderbolt/USB4
driver side of things but may be useful for others too. Not intented to
replace anything we already have for the regular user stack.

In summary this is a collection of small tools that provide bit more
user friendly access to the sysfs/debugfs/tracefs interfaces made
available by the driver. Mainly useful for debugging issues around the
software connection manager parts of the driver (although some of these
work with the firmware connection manager too). We have been using this
internally for a while.

The repository can be found here:

  https://github.com/intel/tbtools

Re: [ANNOUNCE] Thunderbolt/USB4 debugging tools

[Greg KH]

On Tue, Apr 02, 2024 at 01:10:20PM +0300, Mika Westerberg wrote:
> Hi all,
> 
> This is mostly for the folks developing and testing Thunderbolt/USB4
> driver side of things but may be useful for others too. Not intented to
> replace anything we already have for the regular user stack.
> 
> In summary this is a collection of small tools that provide bit more
> user friendly access to the sysfs/debugfs/tracefs interfaces made
> available by the driver. Mainly useful for debugging issues around the
> software connection manager parts of the driver (although some of these
> work with the firmware connection manager too). We have been using this
> internally for a while.
> 
> The repository can be found here:
> 
>   https://github.com/intel/tbtools
> 


Very cool, thanks for the link!

greg k-h

Re: [ANNOUNCE] Thunderbolt/USB4 debugging tools

[Mario Limonciello]

On 4/21/2024 05:27, Greg KH wrote:
> On Tue, Apr 02, 2024 at 01:10:20PM +0300, Mika Westerberg wrote:
>> Hi all,
>>
>> This is mostly for the folks developing and testing Thunderbolt/USB4
>> driver side of things but may be useful for others too. Not intented to
>> replace anything we already have for the regular user stack.
>>
>> In summary this is a collection of small tools that provide bit more
>> user friendly access to the sysfs/debugfs/tracefs interfaces made
>> available by the driver. Mainly useful for debugging issues around the
>> software connection manager parts of the driver (although some of these
>> work with the firmware connection manager too). We have been using this
>> internally for a while.
>>
>> The repository can be found here:
>>
>>    https://github.com/intel/tbtools
>>
> 
> 
> Very cool, thanks for the link!
> 
> greg k-h

Yes, thanks for sharing!  Is it worth adding a link somewhere in kernel 
documentation to make it more discoverable?

Re: [ANNOUNCE] Thunderbolt/USB4 debugging tools

[Mika Westerberg]

On Mon, Apr 22, 2024 at 09:36:24AM -0500, Mario Limonciello wrote:
> On 4/21/2024 05:27, Greg KH wrote:
> > On Tue, Apr 02, 2024 at 01:10:20PM +0300, Mika Westerberg wrote:
> > > Hi all,
> > > 
> > > This is mostly for the folks developing and testing Thunderbolt/USB4
> > > driver side of things but may be useful for others too. Not intented to
> > > replace anything we already have for the regular user stack.
> > > 
> > > In summary this is a collection of small tools that provide bit more
> > > user friendly access to the sysfs/debugfs/tracefs interfaces made
> > > available by the driver. Mainly useful for debugging issues around the
> > > software connection manager parts of the driver (although some of these
> > > work with the firmware connection manager too). We have been using this
> > > internally for a while.
> > > 
> > > The repository can be found here:
> > > 
> > >    https://github.com/intel/tbtools
> > > 
> > 
> > 
> > Very cool, thanks for the link!
> > 
> > greg k-h
> 
> Yes, thanks for sharing!  Is it worth adding a link somewhere in kernel
> documentation to make it more discoverable?

I can't think of any place where this could belong though since this is
not meant for ordinary users (so I guess admin-guide is not good place
for it either).

Re: [ANNOUNCE] Thunderbolt/USB4 debugging tools

[Mika Westerberg]

On Tue, Apr 23, 2024 at 08:36:36AM +0300, Mika Westerberg wrote:
> On Mon, Apr 22, 2024 at 09:36:24AM -0500, Mario Limonciello wrote:
> > On 4/21/2024 05:27, Greg KH wrote:
> > > On Tue, Apr 02, 2024 at 01:10:20PM +0300, Mika Westerberg wrote:
> > > > Hi all,
> > > > 
> > > > This is mostly for the folks developing and testing Thunderbolt/USB4
> > > > driver side of things but may be useful for others too. Not intented to
> > > > replace anything we already have for the regular user stack.
> > > > 
> > > > In summary this is a collection of small tools that provide bit more
> > > > user friendly access to the sysfs/debugfs/tracefs interfaces made
> > > > available by the driver. Mainly useful for debugging issues around the
> > > > software connection manager parts of the driver (although some of these
> > > > work with the firmware connection manager too). We have been using this
> > > > internally for a while.
> > > > 
> > > > The repository can be found here:
> > > > 
> > > >    https://github.com/intel/tbtools
> > > > 
> > > 
> > > 
> > > Very cool, thanks for the link!
> > > 
> > > greg k-h
> > 
> > Yes, thanks for sharing!  Is it worth adding a link somewhere in kernel
> > documentation to make it more discoverable?
> 
> I can't think of any place where this could belong though since this is
> not meant for ordinary users (so I guess admin-guide is not good place
> for it either).

Well maybe as part of the Kconfig, something like below? Does that make
sense?

diff --git a/drivers/thunderbolt/Kconfig b/drivers/thunderbolt/Kconfig
index 279de1ba4487..0abdb69ee9f4 100644
--- a/drivers/thunderbolt/Kconfig
+++ b/drivers/thunderbolt/Kconfig
@@ -22,7 +22,11 @@ config USB4_DEBUGFS_WRITE
 	bool "Enable write by debugfs to configuration spaces (DANGEROUS)"
 	help
 	  Enables writing to device configuration registers through
-	  debugfs interface.
+	  debugfs interface. You can use tools such as Thunderbolt/USB4
+	  debugging tools to access these registers. For more
+	  information see:
+
+	    https://github.com/intel/tbtools
 
 	  Only enable this if you know what you are doing! Never enable
 	  this for production systems or distro kernels.

Re: [ANNOUNCE] Thunderbolt/USB4 debugging tools

[Mario Limonciello]

On 4/23/2024 02:14, Mika Westerberg wrote:
> On Tue, Apr 23, 2024 at 08:36:36AM +0300, Mika Westerberg wrote:
>> On Mon, Apr 22, 2024 at 09:36:24AM -0500, Mario Limonciello wrote:
>>> On 4/21/2024 05:27, Greg KH wrote:
>>>> On Tue, Apr 02, 2024 at 01:10:20PM +0300, Mika Westerberg wrote:
>>>>> Hi all,
>>>>>
>>>>> This is mostly for the folks developing and testing Thunderbolt/USB4
>>>>> driver side of things but may be useful for others too. Not intented to
>>>>> replace anything we already have for the regular user stack.
>>>>>
>>>>> In summary this is a collection of small tools that provide bit more
>>>>> user friendly access to the sysfs/debugfs/tracefs interfaces made
>>>>> available by the driver. Mainly useful for debugging issues around the
>>>>> software connection manager parts of the driver (although some of these
>>>>> work with the firmware connection manager too). We have been using this
>>>>> internally for a while.
>>>>>
>>>>> The repository can be found here:
>>>>>
>>>>>     https://github.com/intel/tbtools
>>>>>
>>>>
>>>>
>>>> Very cool, thanks for the link!
>>>>
>>>> greg k-h
>>>
>>> Yes, thanks for sharing!  Is it worth adding a link somewhere in kernel
>>> documentation to make it more discoverable?
>>
>> I can't think of any place where this could belong though since this is
>> not meant for ordinary users (so I guess admin-guide is not good place
>> for it either).
> 
> Well maybe as part of the Kconfig, something like below? Does that make
> sense?
> 
> diff --git a/drivers/thunderbolt/Kconfig b/drivers/thunderbolt/Kconfig
> index 279de1ba4487..0abdb69ee9f4 100644
> --- a/drivers/thunderbolt/Kconfig
> +++ b/drivers/thunderbolt/Kconfig
> @@ -22,7 +22,11 @@ config USB4_DEBUGFS_WRITE
>   	bool "Enable write by debugfs to configuration spaces (DANGEROUS)"
>   	help
>   	  Enables writing to device configuration registers through
> -	  debugfs interface.
> +	  debugfs interface. You can use tools such as Thunderbolt/USB4
> +	  debugging tools to access these registers. For more
> +	  information see:
> +
> +	    https://github.com/intel/tbtools
>   
>   	  Only enable this if you know what you are doing! Never enable
>   	  this for production systems or distro kernels.

WFM.

Feel free to tag this into the proper patch when you do it.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>