Re: [PATCH v2 0/3] media: add v4l2_subdev_state_xlate_streams()

[Cosmin Tanislav <demonsingur@gmail.com>]

On 2/20/25 1:38 PM, Jacopo Mondi wrote:
> Hi Cosmin
> 
> On Thu, Feb 20, 2025 at 11:20:32AM +0200, Cosmin Tanislav wrote:
>> Currently, the v4l2_subdev_state_xlate_streams() function is used
>> to translate streams from one pad to another.
>> This function takes the entire subdev state as argument, but only makes
>> use of the routing.
> 
> Correct, but is this a problem ?
> 

No, it's not a problem.

> Is this the first step for a larger rework or is this a drive-by
> beautification ?
> 

Mostly a drive-by beautification to avoid passing the whole state around
where we only need the routing. I'm planning to submit drivers for more
GMSL2/3 chips and we're using this just to not pass the whole state
around. I think I can just use v4l2_subdev_state_xlate_streams(),
but I had these patches in my tree and it would have been good to get
them upstream, in preparations for submitting the GMSL2/3 drivers.

> I'm asking because (and I know it's hard to strike a balance) this
> kind of changes tend to make back-porting a more painful, and if
> only justified by "it looks better" I would be a bit hesitant in
> taking them.
> 
> 
>>
>> Introduce a v4l2_subdev_routing_xlate_streams() function which can be
>> used without the entire subdev state, to avoid passing the entire state
>> around when not needed.
>>
>> Convert all usages of v4l2_subdev_state_xlate_streams() to
>> v4l2_subdev_routing_xlate_streams().
>>
>> Remove v4l2_subdev_state_xlate_streams().
>>
>> V2:
>>    * Fix description of parameters
>>
>> Cosmin Tanislav (3):
>>    media: v4l: subdev: add v4l2_subdev_routing_xlate_streams()
>>    media: use v4l2_subdev_routing_xlate_streams()
>>    media: v4l: subdev: remove v4l2_subdev_state_xlate_streams()
>>
>>   drivers/media/i2c/ds90ub913.c                 | 14 ++++++-----
>>   drivers/media/i2c/ds90ub953.c                 | 14 ++++++-----
>>   drivers/media/i2c/max96714.c                  | 16 ++++++-------
>>   drivers/media/i2c/max96717.c                  | 23 ++++++++++---------
>>   drivers/media/pci/intel/ipu6/ipu6-isys-csi2.c | 14 ++++++-----
>>   .../platform/nxp/imx8-isi/imx8-isi-crossbar.c |  2 +-
>>   drivers/media/v4l2-core/v4l2-subdev.c         |  7 +++---
>>   include/media/v4l2-subdev.h                   | 10 ++++----
>>   8 files changed, 53 insertions(+), 47 deletions(-)
>>
>> --
>> 2.48.1
>>
>>