Re: [PATCH v4 1/3] media: ipu-bridge: Add DMI information of Lenovo X9 to the image upside-down list

["Mark Pearson" <mpearson@squebb.ca>]

On Thu, Jun 11, 2026, at 8:44 AM, Sakari Ailus wrote:
> Hi Damjan,
>
> On Thu, Jun 11, 2026 at 11:41:19AM +0200, Damjan Georgievski wrote:
>> On Thu, 11 Jun 2026 at 10:24, Sakari Ailus <sakari.ailus@linux.intel.com> wrote:
>> >
>> > Hi Kate,
>> >
>> > On Thu, Jun 11, 2026 at 03:25:46PM +0800, Kate Hsuan wrote:
>> > > Hi Sakari and Mark,
>> > >
>> > > On Thu, Jun 11, 2026 at 5:59 AM Sakari Ailus
>> > > <sakari.ailus@linux.intel.com> wrote:
>> > > >
>> > > > Hi Kate,
>> > > >
>> > > > I know several people have given you different advices but...
>> > > >
>> > > > On Tue, Jun 09, 2026 at 08:49:24PM +0800, Kate Hsuan wrote:
>> > > > > The Lenovo X9 has an upside-down-mounted Sony IMX471 sensor so the image
>> > > > > was displayed upside-down. Add the DMI information of Lenovo X9 to
>> > > > > resolve the issue.
>> > > > >
>> > > > > Signed-off-by: Kate Hsuan <hpa@redhat.com>
>> > > > > ---
>> > > > >  drivers/media/pci/intel/ipu-bridge.c | 32 ++++++++++++++++++++++++++++
>> > > > >  1 file changed, 32 insertions(+)
>> > > > >
>> > > > > diff --git a/drivers/media/pci/intel/ipu-bridge.c b/drivers/media/pci/intel/ipu-bridge.c
>> > > > > index fc6608e33de4..9e24aaceecdf 100644
>> > > > > --- a/drivers/media/pci/intel/ipu-bridge.c
>> > > > > +++ b/drivers/media/pci/intel/ipu-bridge.c
>> > > > > @@ -134,6 +134,38 @@ static const struct dmi_system_id upside_down_sensor_dmi_ids[] = {
>> > > > >               },
>> > > > >               .driver_data = "OVTI02C1",
>> > > > >       },
>> > > > > +     {
>> > > > > +             /* Lenovo X9-14 */
>> > > > > +             .matches = {
>> > > > > +                     DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
>> > > > > +                     DMI_MATCH(DMI_BOARD_NAME, "21QA"),
>> > > > > +             },
>> > > > > +             .driver_data = "SONY471A",
>> > > > > +     },
>> > > > > +     {
>> > > > > +             /* Lenovo X9-14 */
>> > > >
>> > > > How are the two X9-14's different? It'd be good to have some comment here
>> > > > which model this actually is: the board name is only available (typically
>> > > > at least) in DMI.
>> > >
>> > > According to the datasheet of X9-14 and 15. Lenovo offers 2 screen
>> > > sizes (14-inch and 15-inch) and 2 CPU types (Core Ultra 5 and 7).
>> >
>> > Is the CPU SKU the difference here? If so, can you add that to the comment?
>> >
>> > > They may ship customised firmware for a specific purpose with a random
>> > > DMI_PRODUCT_VERSION.
>> > > So, using the DMI_BOARD_NAME prefix to identify the laptop SKU is
>> > > safer and easier.
>> > >
>> > > I think DMI_MATCH(DMI_BOARD_NAME, "21Q") covers all X9 but I don't
>> > > know the side effect :(
>> > > They may propose a new model with a different MIPI camera or HID.
>> >
>> > Indeed. Is the BOARD_NAME guaranteed to be unique by Lenovo? I think I'd
>> > use DMI_EXACT_MATCH(), too.
>> 
>> The full board_name is 21QA0048RM (on mine), so 21QA is just the prefix.
>> The lenovo support site only requires this prefix to get you to the
>> support page for the laptops and they refer to it as "Type 21QA".
>> 
>> Is there DMI_MATCH_PREFIX, for these (if not all) Thinkpads it might
>> make the most sense ?
>
> DMI_MATCH() only matches for prefix whereas DMI_EXACT_MATCH() requires an
> exact match.
>
There are two BOARD_NAME's for every Thinkpad (which one your system has depends on the channel thru which the platform is sold).

The first 4 chars are the important bit - they are defined and won't change (they are used internally here). The rest of the BOARD_NAME is based on the config and can vary.
I'm not so sure on the PRODUCT_VERSION I'm afraid which is why I'm hesitant to use it, even though doing the match on two IDs is annoying. I'm trying to confirm if it's a good idea or not.

A useful trick, for released platforms, is to go to https://psref.lenovo.com and type your platform in the search bar and it will come up with the match and also list the two board codes.
So if you put in X9-14 you should see 21QA and 21QB - these are the two DMI matches you would need to do (X9-15 uses 21Q6 & 21Q7)

Don't do a match on 21Q - that will definitely match up with other platforms that won't want this change.

Hope that helps
Mark