[PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Hans de Goede]

Add "INTC10D2" ACPI device-id for MTL-CVF devices, like the Dell Latitude
7450.

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2368506
Signed-off-by: Hans de Goede <hansg@kernel.org>
---
Note this applies on top of the addition of the new i2c-usbio driver which
is being merged through gregkh/usb.git usb-next
---
 drivers/i2c/busses/i2c-usbio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/busses/i2c-usbio.c b/drivers/i2c/busses/i2c-usbio.c
index d42f9ab6e9a5..e7799abf6787 100644
--- a/drivers/i2c/busses/i2c-usbio.c
+++ b/drivers/i2c/busses/i2c-usbio.c
@@ -27,6 +27,7 @@ static const struct acpi_device_id usbio_i2c_acpi_hids[] = {
 	{ "INTC1008" }, /* MTL */
 	{ "INTC10B3" }, /* ARL */
 	{ "INTC10B6" }, /* LNL */
+	{ "INTC10D2" }, /* MTL-CVF */
 	{ "INTC10E3" }, /* PTL */
 	{ }
 };
-- 
2.51.0

Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Sakari Ailus]

Hi Hans,

On Wed, Oct 01, 2025 at 11:23:10PM +0200, Hans de Goede wrote:
> Add "INTC10D2" ACPI device-id for MTL-CVF devices, like the Dell Latitude
> 7450.
> 
> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2368506
> Signed-off-by: Hans de Goede <hansg@kernel.org>
> ---
> Note this applies on top of the addition of the new i2c-usbio driver which
> is being merged through gregkh/usb.git usb-next
> ---
>  drivers/i2c/busses/i2c-usbio.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/i2c/busses/i2c-usbio.c b/drivers/i2c/busses/i2c-usbio.c
> index d42f9ab6e9a5..e7799abf6787 100644
> --- a/drivers/i2c/busses/i2c-usbio.c
> +++ b/drivers/i2c/busses/i2c-usbio.c
> @@ -27,6 +27,7 @@ static const struct acpi_device_id usbio_i2c_acpi_hids[] = {
>  	{ "INTC1008" }, /* MTL */
>  	{ "INTC10B3" }, /* ARL */
>  	{ "INTC10B6" }, /* LNL */
> +	{ "INTC10D2" }, /* MTL-CVF */

INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
an actual system that uses USBIO and this HID?

>  	{ "INTC10E3" }, /* PTL */
>  	{ }
>  };

-- 
Kind regards,

Sakari Ailus

Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Sakari Ailus]

Hi Hans, Lixu,

On Thu, Oct 02, 2025 at 12:58:07AM +0300, Sakari Ailus wrote:
> Hi Hans,
> 
> On Wed, Oct 01, 2025 at 11:23:10PM +0200, Hans de Goede wrote:
> > Add "INTC10D2" ACPI device-id for MTL-CVF devices, like the Dell Latitude
> > 7450.
> > 
> > Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2368506
> > Signed-off-by: Hans de Goede <hansg@kernel.org>
> > ---
> > Note this applies on top of the addition of the new i2c-usbio driver which
> > is being merged through gregkh/usb.git usb-next
> > ---
> >  drivers/i2c/busses/i2c-usbio.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/i2c/busses/i2c-usbio.c b/drivers/i2c/busses/i2c-usbio.c
> > index d42f9ab6e9a5..e7799abf6787 100644
> > --- a/drivers/i2c/busses/i2c-usbio.c
> > +++ b/drivers/i2c/busses/i2c-usbio.c
> > @@ -27,6 +27,7 @@ static const struct acpi_device_id usbio_i2c_acpi_hids[] = {
> >  	{ "INTC1008" }, /* MTL */
> >  	{ "INTC10B3" }, /* ARL */
> >  	{ "INTC10B6" }, /* LNL */
> > +	{ "INTC10D2" }, /* MTL-CVF */
> 
> INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
> an actual system that uses USBIO and this HID?

Actually it looks like i2c-ljca.c shouldn't list this HID. The same
probably goes for all 10CF--10D3.

Lixu: any idea?

I thought USBIO always came with CVS but that doesn't seem to be the case
here.

> 
> >  	{ "INTC10E3" }, /* PTL */
> >  	{ }
> >  };
> 

-- 
Regards,

Sakari Ailus

Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Hans de Goede]

Hi,

First of all I messed up the git format-patch command,
there is no second patch in this series.

(at least not for the i2c subsystem. There is a similar GPIO
patch but I send that out separately)

On 1-Oct-25 11:58 PM, Sakari Ailus wrote:
> Hi Hans,
> 
> On Wed, Oct 01, 2025 at 11:23:10PM +0200, Hans de Goede wrote:
>> Add "INTC10D2" ACPI device-id for MTL-CVF devices, like the Dell Latitude
>> 7450.
>>
>> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2368506
>> Signed-off-by: Hans de Goede <hansg@kernel.org>
>> ---
>> Note this applies on top of the addition of the new i2c-usbio driver which
>> is being merged through gregkh/usb.git usb-next
>> ---
>>  drivers/i2c/busses/i2c-usbio.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/i2c/busses/i2c-usbio.c b/drivers/i2c/busses/i2c-usbio.c
>> index d42f9ab6e9a5..e7799abf6787 100644
>> --- a/drivers/i2c/busses/i2c-usbio.c
>> +++ b/drivers/i2c/busses/i2c-usbio.c
>> @@ -27,6 +27,7 @@ static const struct acpi_device_id usbio_i2c_acpi_hids[] = {
>>  	{ "INTC1008" }, /* MTL */
>>  	{ "INTC10B3" }, /* ARL */
>>  	{ "INTC10B6" }, /* LNL */
>> +	{ "INTC10D2" }, /* MTL-CVF */
> 
> INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
> an actual system that uses USBIO and this HID?

Yes, see the Closes: tag which points to a bug-report which such a system:

https://bugzilla.redhat.com/show_bug.cgi?id=2368506

Let me also reply to your other comment here:

>> INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
>> an actual system that uses USBIO and this HID?
> 
> Actually it looks like i2c-ljca.c shouldn't list this HID. The same
> probably goes for all 10CF--10D3.

I would not be so sure of this, there are at least some Dell systems
which use a combination of ljca and Meteor Lake and I believe these
do use the "INTC10D2" HID with LJCA for the I2C part and the same
goes for the GPIO / SPI parts.. One example of such a system is
the Dell Precision 5490.

The way these Intel uses these HIDs is really weird they seem to
simply mean "I2C" on *a* USBIO expander with this generation CPU.

Where there really seems no reason to change the HID for CPU
generations, where as it would be a good reason to change the HID
if the actual USBIO expander is different ...

Regards,

Hans

Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Sakari Ailus]

Hi Hans,

On Thu, Oct 02, 2025 at 10:56:47AM +0200, Hans de Goede wrote:
> Hi,
> 
> First of all I messed up the git format-patch command,
> there is no second patch in this series.
> 
> (at least not for the i2c subsystem. There is a similar GPIO
> patch but I send that out separately)
> 
> On 1-Oct-25 11:58 PM, Sakari Ailus wrote:
> > Hi Hans,
> > 
> > On Wed, Oct 01, 2025 at 11:23:10PM +0200, Hans de Goede wrote:
> >> Add "INTC10D2" ACPI device-id for MTL-CVF devices, like the Dell Latitude
> >> 7450.
> >>
> >> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2368506
> >> Signed-off-by: Hans de Goede <hansg@kernel.org>
> >> ---
> >> Note this applies on top of the addition of the new i2c-usbio driver which
> >> is being merged through gregkh/usb.git usb-next
> >> ---
> >>  drivers/i2c/busses/i2c-usbio.c | 1 +
> >>  1 file changed, 1 insertion(+)
> >>
> >> diff --git a/drivers/i2c/busses/i2c-usbio.c b/drivers/i2c/busses/i2c-usbio.c
> >> index d42f9ab6e9a5..e7799abf6787 100644
> >> --- a/drivers/i2c/busses/i2c-usbio.c
> >> +++ b/drivers/i2c/busses/i2c-usbio.c
> >> @@ -27,6 +27,7 @@ static const struct acpi_device_id usbio_i2c_acpi_hids[] = {
> >>  	{ "INTC1008" }, /* MTL */
> >>  	{ "INTC10B3" }, /* ARL */
> >>  	{ "INTC10B6" }, /* LNL */
> >> +	{ "INTC10D2" }, /* MTL-CVF */
> > 
> > INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
> > an actual system that uses USBIO and this HID?
> 
> Yes, see the Closes: tag which points to a bug-report which such a system:
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=2368506
> 
> Let me also reply to your other comment here:
> 
> >> INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
> >> an actual system that uses USBIO and this HID?
> > 
> > Actually it looks like i2c-ljca.c shouldn't list this HID. The same
> > probably goes for all 10CF--10D3.
> 
> I would not be so sure of this, there are at least some Dell systems
> which use a combination of ljca and Meteor Lake and I believe these
> do use the "INTC10D2" HID with LJCA for the I2C part and the same
> goes for the GPIO / SPI parts.. One example of such a system is
> the Dell Precision 5490.

LJCA on MTL is supposed to be 1008. Do you have the *SDT so we could verify
this?

> 
> The way these Intel uses these HIDs is really weird they seem to
> simply mean "I2C" on *a* USBIO expander with this generation CPU.

I can assure you I have nothing to do with this ACPI ID usage scheme. :-)

> 
> Where there really seems no reason to change the HID for CPU
> generations, where as it would be a good reason to change the HID
> if the actual USBIO expander is different ...

That's indeed supposed to be the case. Also the _HID should always reflect
the actual device and only _CID should indicate it's compatible with
something else. But that BIOS is already out there so there's little that
can be done to it anyway. :-\

-- 
Regards,

Sakari Ailus

Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Hans de Goede]

Hi,

On 2-Oct-25 11:18 AM, Sakari Ailus wrote:
> Hi Hans,
> 
> On Thu, Oct 02, 2025 at 10:56:47AM +0200, Hans de Goede wrote:
>> Hi,
>>
>> First of all I messed up the git format-patch command,
>> there is no second patch in this series.
>>
>> (at least not for the i2c subsystem. There is a similar GPIO
>> patch but I send that out separately)
>>
>> On 1-Oct-25 11:58 PM, Sakari Ailus wrote:
>>> Hi Hans,
>>>
>>> On Wed, Oct 01, 2025 at 11:23:10PM +0200, Hans de Goede wrote:
>>>> Add "INTC10D2" ACPI device-id for MTL-CVF devices, like the Dell Latitude
>>>> 7450.
>>>>
>>>> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2368506
>>>> Signed-off-by: Hans de Goede <hansg@kernel.org>
>>>> ---
>>>> Note this applies on top of the addition of the new i2c-usbio driver which
>>>> is being merged through gregkh/usb.git usb-next
>>>> ---
>>>>  drivers/i2c/busses/i2c-usbio.c | 1 +
>>>>  1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/drivers/i2c/busses/i2c-usbio.c b/drivers/i2c/busses/i2c-usbio.c
>>>> index d42f9ab6e9a5..e7799abf6787 100644
>>>> --- a/drivers/i2c/busses/i2c-usbio.c
>>>> +++ b/drivers/i2c/busses/i2c-usbio.c
>>>> @@ -27,6 +27,7 @@ static const struct acpi_device_id usbio_i2c_acpi_hids[] = {
>>>>  	{ "INTC1008" }, /* MTL */
>>>>  	{ "INTC10B3" }, /* ARL */
>>>>  	{ "INTC10B6" }, /* LNL */
>>>> +	{ "INTC10D2" }, /* MTL-CVF */
>>>
>>> INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
>>> an actual system that uses USBIO and this HID?
>>
>> Yes, see the Closes: tag which points to a bug-report which such a system:
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=2368506
>>
>> Let me also reply to your other comment here:
>>
>>>> INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
>>>> an actual system that uses USBIO and this HID?
>>>
>>> Actually it looks like i2c-ljca.c shouldn't list this HID. The same
>>> probably goes for all 10CF--10D3.
>>
>> I would not be so sure of this, there are at least some Dell systems
>> which use a combination of ljca and Meteor Lake and I believe these
>> do use the "INTC10D2" HID with LJCA for the I2C part and the same
>> goes for the GPIO / SPI parts.. One example of such a system is
>> the Dell Precision 5490.
> 
> LJCA on MTL is supposed to be 1008. Do you have the *SDT so we could verify
> this?

I only had this laptop for a short while since it was using LJCA + IVSC
it was not really an interesting device to hold on to. A Red Hat colleague
of mine has the laptop now.

I'll inquiry about getting ssh access to it to collect acpidumps
and also to directly get the used HIDs from sysfs (SSDTs now a days
are often unreadable because of them dynamically assigning HIDs
based on BIOS config variables).

>> The way these Intel uses these HIDs is really weird they seem to
>> simply mean "I2C" on *a* USBIO expander with this generation CPU.
> 
> I can assure you I have nothing to do with this ACPI ID usage scheme. :-)
> 
>>
>> Where there really seems no reason to change the HID for CPU
>> generations, where as it would be a good reason to change the HID
>> if the actual USBIO expander is different ...
> 
> That's indeed supposed to be the case. Also the _HID should always reflect
> the actual device and only _CID should indicate it's compatible with
> something else. But that BIOS is already out there so there's little that
> can be done to it anyway. :-\

Ack.

Regards,

Hans

Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Hans de Goede]

Hi,

On 2-Oct-25 11:18 AM, Sakari Ailus wrote:
> Hi Hans,
> 
> On Thu, Oct 02, 2025 at 10:56:47AM +0200, Hans de Goede wrote:
>> Hi,

...

>>>> INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
>>>> an actual system that uses USBIO and this HID?
>>>
>>> Actually it looks like i2c-ljca.c shouldn't list this HID. The same
>>> probably goes for all 10CF--10D3.
>>
>> I would not be so sure of this, there are at least some Dell systems
>> which use a combination of ljca and Meteor Lake and I believe these
>> do use the "INTC10D2" HID with LJCA for the I2C part and the same
>> goes for the GPIO / SPI parts.. One example of such a system is
>> the Dell Precision 5490.
> 
> LJCA on MTL is supposed to be 1008. Do you have the *SDT so we could verify
> this?

I just checked this in a ssh session to the Dell Precision 5490:

hans@prdel:~$ cd /sys/bus/auxiliary/devices/
hans@prdel:/sys/bus/auxiliary/devices$ ls
intel_ipu6.isys.40      intel_vsec.telemetry.2  soundwire_intel.link.2  usb_ljca.ljca-i2c.1
intel_ipu6.psys.40      snd_sof.hda-probes.0    soundwire_intel.link.3  usb_ljca.ljca-spi.0
intel_vsec.telemetry.0  soundwire_intel.link.0  usb_ljca.ljca-gpio.0
intel_vsec.telemetry.1  soundwire_intel.link.1  usb_ljca.ljca-i2c.0
hans@prdel:/sys/bus/auxiliary/devices$ cat usb_ljca.ljca-*/firmware_node/hid 
INTC10D1
INTC10D2
INTC10D2
INTC10D3

So as you can see this really is using the INTC10D* HIDs and these
are thus duplicate between the LJCA and USBIO IO-expanders.

Note this does not really cause problems since we have the USB driver
binding by USB VID:PID first and only then the code looks for
the ACPI HIDs for the GPIO/I2C/SPI children so at this point we are
already in LJCA resp. USBIO specific code-paths.

I've also asked for an acpidump, do you still want that once I receive it ?

Regards,

Hans

RE: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Cepeda Lopez, Israel A]

Hi Hans,

LJCA and USBIO shouldn't be sharing HIDs. What is the USB IO expander in that system (lsusb)?

> -----Original Message-----
> From: Hans de Goede <hansg@kernel.org>
> Sent: Thursday, October 2, 2025 6:05 AM
> To: Sakari Ailus <sakari.ailus@linux.intel.com>
> Cc: Cepeda Lopez, Israel A <israel.a.cepeda.lopez@intel.com>; Andi Shyti
> <andi.shyti@kernel.org>; Wolfram Sang <wsa+renesas@sang-engineering.com>;
> linux-i2c@vger.kernel.org
> Subject: Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices
> 
> Hi,
> 
> On 2-Oct-25 11:18 AM, Sakari Ailus wrote:
> > Hi Hans,
> >
> > On Thu, Oct 02, 2025 at 10:56:47AM +0200, Hans de Goede wrote:
> >> Hi,
> 
> ...
> 
> >>>> INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
> >>>> an actual system that uses USBIO and this HID?
> >>>
> >>> Actually it looks like i2c-ljca.c shouldn't list this HID. The same
> >>> probably goes for all 10CF--10D3.
> >>
> >> I would not be so sure of this, there are at least some Dell systems
> >> which use a combination of ljca and Meteor Lake and I believe these
> >> do use the "INTC10D2" HID with LJCA for the I2C part and the same
> >> goes for the GPIO / SPI parts.. One example of such a system is
> >> the Dell Precision 5490.
> >
> > LJCA on MTL is supposed to be 1008. Do you have the *SDT so we could verify
> > this?
> 
> I just checked this in a ssh session to the Dell Precision 5490:
> 
> hans@prdel:~$ cd /sys/bus/auxiliary/devices/
> hans@prdel:/sys/bus/auxiliary/devices$ ls
> intel_ipu6.isys.40      intel_vsec.telemetry.2  soundwire_intel.link.2  usb_ljca.ljca-
> i2c.1
> intel_ipu6.psys.40      snd_sof.hda-probes.0    soundwire_intel.link.3  usb_ljca.ljca-
> spi.0
> intel_vsec.telemetry.0  soundwire_intel.link.0  usb_ljca.ljca-gpio.0
> intel_vsec.telemetry.1  soundwire_intel.link.1  usb_ljca.ljca-i2c.0
> hans@prdel:/sys/bus/auxiliary/devices$ cat usb_ljca.ljca-*/firmware_node/hid
> INTC10D1
> INTC10D2
> INTC10D2
> INTC10D3
> 
> So as you can see this really is using the INTC10D* HIDs and these
> are thus duplicate between the LJCA and USBIO IO-expanders.
> 
> Note this does not really cause problems since we have the USB driver
> binding by USB VID:PID first and only then the code looks for
> the ACPI HIDs for the GPIO/I2C/SPI children so at this point we are
> already in LJCA resp. USBIO specific code-paths.
> 
> I've also asked for an acpidump, do you still want that once I receive it ?
> 
> Regards,
> 
> Hans
> 
> 
> 
> 

Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Hans de Goede]

Hi Israel,

On 2-Oct-25 5:52 PM, Cepeda Lopez, Israel A wrote:
> Hi Hans,
> 
> LJCA and USBIO shouldn't be sharing HIDs.

Yes in practice we have shipping hardware that is sharing HIDs
and since this is hardware out there in the field there is
nothing we can do about this.

> What is the USB IO expander in that system (lsusb)?

Dell Precision 5490: 8086:0b63 usb-ljca device
  with INTC10D1, INTC10D2 and INTC10D3 ACPI children

Dell Latitude 7450: 2ac1:20c9 usbio device
  with INTC10D1 and INTC10D2 ACPI children

As I already mentioned earlier in this thread the shared HIDs are not
really a problem because we have the USB driver binding by USB VID:PID
first and only then the code looks for the ACPI HIDs for the GPIO/I2C/SPI
children so at this point we are already in LJCA resp. USBIO specific
code-paths.

Regards,

Hans

RE: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Cepeda Lopez, Israel A]

Thank you Hans,

> -----Original Message-----
> From: Hans de Goede <hansg@kernel.org>
> Sent: Thursday, October 2, 2025 10:49 AM
> To: Cepeda Lopez, Israel A <israel.a.cepeda.lopez@intel.com>; Sakari Ailus
> <sakari.ailus@linux.intel.com>
> Cc: Andi Shyti <andi.shyti@kernel.org>; Wolfram Sang <wsa+renesas@sang-
> engineering.com>; linux-i2c@vger.kernel.org
> Subject: Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices
> 
> Hi Israel,
> 
> On 2-Oct-25 5:52 PM, Cepeda Lopez, Israel A wrote:
> > Hi Hans,
> >
> > LJCA and USBIO shouldn't be sharing HIDs.
> 
> Yes in practice we have shipping hardware that is sharing HIDs
> and since this is hardware out there in the field there is
> nothing we can do about this.

There is. DELL has to provide a new FW/BIOS update to fix the HID
of the system on fault. That is the correct solution to the issue.

> 
> > What is the USB IO expander in that system (lsusb)?
> 
> Dell Precision 5490: 8086:0b63 usb-ljca device
>   with INTC10D1, INTC10D2 and INTC10D3 ACPI children
> 
> Dell Latitude 7450: 2ac1:20c9 usbio device
>   with INTC10D1 and INTC10D2 ACPI children
> 
> As I already mentioned earlier in this thread the shared HIDs are not
> really a problem because we have the USB driver binding by USB VID:PID
> first and only then the code looks for the ACPI HIDs for the GPIO/I2C/SPI
> children so at this point we are already in LJCA resp. USBIO specific
> code-paths.

Agree that there is no driver problem, but it will be better to have a proper solution and avoid further confusion.

Thank you for noticing and bringing this to our attention.

> 
> Regards,
> 
> Hans
> 
> 

Re: RE: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Hans de Goede]

Hi Israel,

On 2-Oct-25 8:05 PM, Cepeda Lopez, Israel A wrote:
> Thank you Hans,
> 
>> -----Original Message-----
>> From: Hans de Goede <hansg@kernel.org>
>> Sent: Thursday, October 2, 2025 10:49 AM
>> To: Cepeda Lopez, Israel A <israel.a.cepeda.lopez@intel.com>; Sakari Ailus
>> <sakari.ailus@linux.intel.com>
>> Cc: Andi Shyti <andi.shyti@kernel.org>; Wolfram Sang <wsa+renesas@sang-
>> engineering.com>; linux-i2c@vger.kernel.org
>> Subject: Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices
>>
>> Hi Israel,
>>
>> On 2-Oct-25 5:52 PM, Cepeda Lopez, Israel A wrote:
>>> Hi Hans,
>>>
>>> LJCA and USBIO shouldn't be sharing HIDs.
>>
>> Yes in practice we have shipping hardware that is sharing HIDs
>> and since this is hardware out there in the field there is
>> nothing we can do about this.
> 
> There is. DELL has to provide a new FW/BIOS update to fix the HID
> of the system on fault. That is the correct solution to the issue.

Even if Dell is willing to do this (which I find unlikely)
it will still likely take at least 6 months for a BIOS update
to show up with these changes (BIOS QA takes a lot of time in
my experience).

And even then we cannot count on users to actually install BIOS
updates. So we will still need the INTC10D1, INTC10D2 and
INTC10D3 HIDs in both the ljca and usbio drivers to support
people who are still at the older BIOS.

And if I've understood Sakari correct then the INTC10D1, INTC10D2
HIDs are indeed intended for use with the USBIO driver and
the problem is that ideally they should not also be used by
the LJCA driver.

Since this patch adds the HIDs to the USBIO drivers, where they
belong the whole discussion of them not supposed to be in the LJCA
driver is sort of offtopic and this patch is correct regardless.

As such can you please give your Acked-by or Reviewed-by
for this patch and for the matching GPIO patch:

https://lore.kernel.org/linux-gpio/20251001212416.4871-1-hansg@kernel.org/

Regards,

Hans

RE: RE: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Cepeda Lopez, Israel A]

Hi Hans,

> -----Original Message-----
> From: Hans de Goede <hansg@kernel.org>
> Sent: Saturday, October 4, 2025 7:04 AM
> To: Cepeda Lopez, Israel A <israel.a.cepeda.lopez@intel.com>; Sakari Ailus
> <sakari.ailus@linux.intel.com>
> Cc: Andi Shyti <andi.shyti@kernel.org>; Wolfram Sang <wsa+renesas@sang-
> engineering.com>; linux-i2c@vger.kernel.org
> Subject: Re: RE: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices
> 
> Hi Israel,
> 
> On 2-Oct-25 8:05 PM, Cepeda Lopez, Israel A wrote:
> > Thank you Hans,
> >
> >> -----Original Message-----
> >> From: Hans de Goede <hansg@kernel.org>
> >> Sent: Thursday, October 2, 2025 10:49 AM
> >> To: Cepeda Lopez, Israel A <israel.a.cepeda.lopez@intel.com>; Sakari Ailus
> >> <sakari.ailus@linux.intel.com>
> >> Cc: Andi Shyti <andi.shyti@kernel.org>; Wolfram Sang <wsa+renesas@sang-
> >> engineering.com>; linux-i2c@vger.kernel.org
> >> Subject: Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices
> >>
> >> Hi Israel,
> >>
> >> On 2-Oct-25 5:52 PM, Cepeda Lopez, Israel A wrote:
> >>> Hi Hans,
> >>>
> >>> LJCA and USBIO shouldn't be sharing HIDs.
> >>
> >> Yes in practice we have shipping hardware that is sharing HIDs
> >> and since this is hardware out there in the field there is
> >> nothing we can do about this.
> >
> > There is. DELL has to provide a new FW/BIOS update to fix the HID
> > of the system on fault. That is the correct solution to the issue.
> 
> Even if Dell is willing to do this (which I find unlikely)
> it will still likely take at least 6 months for a BIOS update
> to show up with these changes (BIOS QA takes a lot of time in
> my experience).
> 
> And even then we cannot count on users to actually install BIOS
> updates. So we will still need the INTC10D1, INTC10D2 and
> INTC10D3 HIDs in both the ljca and usbio drivers to support
> people who are still at the older BIOS.

Agree. Let's proceed with change. Thanks

> 
> And if I've understood Sakari correct then the INTC10D1, INTC10D2
> HIDs are indeed intended for use with the USBIO driver and
> the problem is that ideally they should not also be used by
> the LJCA driver.
> 
> Since this patch adds the HIDs to the USBIO drivers, where they
> belong the whole discussion of them not supposed to be in the LJCA
> driver is sort of offtopic and this patch is correct regardless.
> 
> As such can you please give your Acked-by or Reviewed-by
> for this patch and for the matching GPIO patch:

Acked-by: Israel Cepeda <israel.a.cepeda.lopez@intel.com>

> 
> https://lore.kernel.org/linux-gpio/20251001212416.4871-1-hansg@kernel.org/
> 
> Regards,
> 
> Hans

Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Sakari Ailus]

Hi Hans,

On Thu, Oct 02, 2025 at 03:04:30PM +0200, Hans de Goede wrote:
> Hi,
> 
> On 2-Oct-25 11:18 AM, Sakari Ailus wrote:
> > Hi Hans,
> > 
> > On Thu, Oct 02, 2025 at 10:56:47AM +0200, Hans de Goede wrote:
> >> Hi,
> 
> ...
> 
> >>>> INTC10D2 is apparently already claimed by the LJCA I²C driver. Do you have
> >>>> an actual system that uses USBIO and this HID?
> >>>
> >>> Actually it looks like i2c-ljca.c shouldn't list this HID. The same
> >>> probably goes for all 10CF--10D3.
> >>
> >> I would not be so sure of this, there are at least some Dell systems
> >> which use a combination of ljca and Meteor Lake and I believe these
> >> do use the "INTC10D2" HID with LJCA for the I2C part and the same
> >> goes for the GPIO / SPI parts.. One example of such a system is
> >> the Dell Precision 5490.
> > 
> > LJCA on MTL is supposed to be 1008. Do you have the *SDT so we could verify
> > this?
> 
> I just checked this in a ssh session to the Dell Precision 5490:
> 
> hans@prdel:~$ cd /sys/bus/auxiliary/devices/
> hans@prdel:/sys/bus/auxiliary/devices$ ls
> intel_ipu6.isys.40      intel_vsec.telemetry.2  soundwire_intel.link.2  usb_ljca.ljca-i2c.1
> intel_ipu6.psys.40      snd_sof.hda-probes.0    soundwire_intel.link.3  usb_ljca.ljca-spi.0
> intel_vsec.telemetry.0  soundwire_intel.link.0  usb_ljca.ljca-gpio.0
> intel_vsec.telemetry.1  soundwire_intel.link.1  usb_ljca.ljca-i2c.0
> hans@prdel:/sys/bus/auxiliary/devices$ cat usb_ljca.ljca-*/firmware_node/hid 
> INTC10D1
> INTC10D2
> INTC10D2
> INTC10D3
> 
> So as you can see this really is using the INTC10D* HIDs and these
> are thus duplicate between the LJCA and USBIO IO-expanders.

Thanks for confirming this. Luckily this isn't an issue as matching doesn't
use ACPI HIDs. That being said, I really wonder where this stuff comes
from.

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

-- 
Kind regards,

Sakari Ailus

Re: [PATCH 1/2] i2c: usbio: Add ACPI device-id for MTL-CVF devices

[Wolfram Sang]

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On Wed, Oct 01, 2025 at 11:23:10PM +0200, Hans de Goede wrote:
> Add "INTC10D2" ACPI device-id for MTL-CVF devices, like the Dell Latitude
> 7450.
> 
> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2368506
> Signed-off-by: Hans de Goede <hansg@kernel.org>
> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Acked-by: Israel Cepeda <israel.a.cepeda.lopez@intel.com>

With dependencies upstream now, applied to for-current, thanks!


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