linux-kernel - Re: [PATCH v2 05/12] media: ipu-bridge: Use v4l2

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ff8e5e11-6947-4d7e-98fa-26fdd4054a36@kernel.org>
Date: Mon, 14 Jul 2025 15:11:55 +0200
From: Hans de Goede <hansg@...nel.org>
To: Ricardo Ribalda <ribalda@...omium.org>,
 Sakari Ailus <sakari.ailus@...ux.intel.com>
Cc: Laurent Pinchart <laurent.pinchart@...asonboard.com>,
 Mauro Carvalho Chehab <mchehab@...nel.org>, Hans Verkuil
 <hverkuil@...all.nl>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
 Conor Dooley <conor+dt@...nel.org>, Linus Walleij
 <linus.walleij@...aro.org>, Bartosz Golaszewski <brgl@...ev.pl>,
 "Rafael J. Wysocki" <rafael@...nel.org>, Len Brown <lenb@...nel.org>,
 linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-usb@...r.kernel.org, devicetree@...r.kernel.org,
 linux-gpio@...r.kernel.org, linux-acpi@...r.kernel.org
Subject: Re: [PATCH v2 05/12] media: ipu-bridge: Use v4l2_fwnode for unknown
 rotations

Hi,

On 8-Jul-25 16:58, Ricardo Ribalda wrote:
> On Tue, 8 Jul 2025 at 14:21, Sakari Ailus <sakari.ailus@...ux.intel.com> wrote:
>>
>> Hi Ricardo,
>>
>> On Tue, Jul 08, 2025 at 02:09:28PM +0200, Ricardo Ribalda wrote:
>>> On Tue, 8 Jul 2025 at 11:22, Sakari Ailus <sakari.ailus@...ux.intel.com> wrote:
>>>>
>>>> Hi Ricardo,
>>>>
>>>> On Tue, Jul 08, 2025 at 11:16:25AM +0200, Ricardo Ribalda wrote:
>>>>> Hi Sakari
>>>>>
>>>>> Thanks for your review
>>>>>
>>>>> On Mon, 7 Jul 2025 at 23:45, Sakari Ailus <sakari.ailus@...ux.intel.com> wrote:
>>>>>>
>>>>>> Hi Ricardo,
>>>>>>
>>>>>> On Thu, Jun 05, 2025 at 05:52:58PM +0000, Ricardo Ribalda wrote:
>>>>>>> The v4l2_fwnode_device_properties contains information about the
>>>>>>> rotation. Use it if the ssdb data is inconclusive.
>>>>>>
>>>>>> As SSDB and _PLD provide the same information, are they always aligned? Do
>>>>>> you have any experience on how is this actually in firmware?
>>>>>
>>>>> Not really, in ChromeOS we are pretty lucky to control the firmware.
>>>>>
>>>>> @HdG Do you have some experience/opinion here?
>>>>>
>>>>>>
>>>>>> _PLD is standardised so it would seem reasonable to stick to that -- if it
>>>>>> exists. Another approach could be to pick the one that doesn't translate to
>>>>>> a sane default (0°).
>>>>>
>>>>> I'd rather stick to the current prioritization unless there is a
>>>>> strong argument against it. Otherwise there is a chance that we will
>>>>> have regressions (outside CrOS)
>>>>
>>>> My point was rather there are no such rules currently for rotation: only
>>>> SSDB was being used by the IPU bridge to obtain the rotation value,
>>>> similarly only _PLD is consulted when it comes to orientation.
>>>
>>> So something like this:?
>>>
>>> static u32 ipu_bridge_parse_rotation(struct acpi_device *adev,
>>>                                      struct ipu_sensor_ssdb *ssdb,
>>>                                      struct
>>> v4l2_fwnode_device_properties *props)
>>> {
>>>         if (props->rotation != V4L2_FWNODE_PROPERTY_UNSET)
>>>                 return props->rotation;
>>>
>>>         switch (ssdb->degree) {
>>>         case IPU_SENSOR_ROTATION_NORMAL:
>>>                 return 0;
>>>         case IPU_SENSOR_ROTATION_INVERTED:
>>>                 return 180;
>>>         }
>>>
>>>         dev_warn(ADEV_DEV(adev),
>>>                  "Unknown rotation %d. Assume 0 degree rotation\n",
>>>                  ssdb->degree);
>>
>> Maybe:
>>
>>         acpi_handle_warn(acpi_device_handle(adev), ...);
>>
>> ?
>>
>>>         return 0;
>>> }
>>
>> Looks good to me. Maybe something similar for orientation?
> 
> Do you mean using ssdb also for orientation or using acpi_handle_warn?
> 
> 
> I cannot find anything related to orientation for SSDB
> https://github.com/coreboot/coreboot/blob/main/src/drivers/intel/mipi_camera/chip.h#L150
> 
> Am I looking in the right place?

I believe that orientation is only available in the PLD,
so for orientation we can just use the value returned in
v4l2_fwnode_device_properties defaulting to front when
it is not set.

Otherwise I agree with what has been discussed in this
thread (for this patch) so far.

Regards,

Hans