Re: [PATCH 5/8] media: iris: Move vpu register defines to common header file

[Vishnu Reddy]

On 9/25/2025 2:40 PM, Konrad Dybcio wrote:
> On 9/25/25 1:14 AM, Vikash Garodia wrote:
> > Some of vpu4 register defines are common with vpu3x. Move those into the
> > common register defines header. This is done to reuse the defines for
> > vpu4 in subsequent patch which enables the power sequence for vpu4.
> >
> > Co-developed-by: Vishnu Reddy <quic_bvisredd@xxxxxxxxxxx>
> > Signed-off-by: Vishnu Reddy <quic_bvisredd@xxxxxxxxxxx>
> > Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
> > ---
> >   drivers/media/platform/qcom/iris/iris_vpu3x.c      | 36 ----------------------
> >   drivers/media/platform/qcom/iris/iris_vpu_common.c | 23 --------------
> >   .../platform/qcom/iris/iris_vpu_register_defines.h | 29 +++++++++++++++++
>
> This is a slippery slope. I think it's better if you explicitly say
> the header file contains the register map of VPU3 instead, as let's say
> VPU5 may add a random register in the middle (pushing some existing ones
> +0x4 down). Such changes are annoying to debug, and we've unfortunately
> been there on Adreno..
>
> Because you're using this for a single common function that is both acting
> upon the same registers and performing the same operations on them across
> VPU35 and VPU4, it's okay to de-static-ize the function from iris_vpu3.c and
> refer to it from vpu4 ops, keeping the register map private to the former
> file which I think will end up less error-prone for the future.
>
> Konrad

 Just to confirm
 1. You’re saying it’s better to keep the register definitions for each
 VPU generation in their own source files, instead of keeping them all
 in a shared header. Is that right?

 2. The vpu functions (power on controller, power off controller and
 etc.) which are common for vpu3x and vpu4x are moved to
 iris_vpu_common.c and de-static-ize to use for both vpu3x and vpu4x.
 (This code changes are there in [PATCH 6/8] media: iris: Move vpu35
 specific api to common to use for vpu4)

 Will this 2nd point is fine or Do I need the keep the functions also
 in the platform specific file and reuse for vpu4x by de-static-ize the
 function in iris_vpu3x.c?

 Thanks and regards,
 Vishnu Reddy