Re: [PATCH v3 2/7] media: iris: switch to hardware mode after firmware boot

[Dikshita Agarwal <dikshita.agarwal@oss.qualcomm.com>]

On 3/13/2026 6:49 PM, Vikash Garodia wrote:
> Currently the driver switches the vcodec GDSC to hardware (HW) mode
> before firmware load and boot sequence. GDSC can be powered off, keeping
> in hw mode, thereby the vcodec registers programmed in TrustZone (TZ)
> carry default (reset) values.
> Move the transition to HW mode after firmware load and boot sequence.
> 
> The bug was exposed with driver configuring different stream ids to
> different devices via iommu-map. With registers carrying reset values,
> VPU would not generate desired stream-id, thereby leading to SMMU fault.
> 
> For vpu4, when GDSC is switched to HW mode, there is a need to perform
> the reset operation. Without reset, there are occassional issues of
> register corruption observed. Hence the vpu GDSC switch also involves
> the reset.
> 
> Fixes: dde659d37036 ("media: iris: Introduce vpu ops for vpu4 with necessary hooks")
> Co-developed-by: Vishnu Reddy <busanna.reddy@oss.qualcomm.com>
> Signed-off-by: Vishnu Reddy <busanna.reddy@oss.qualcomm.com>
> Signed-off-by: Vikash Garodia <vikash.garodia@oss.qualcomm.com>
> ---
>  drivers/media/platform/qcom/iris/iris_core.c       |  4 ++++
>  drivers/media/platform/qcom/iris/iris_hfi_common.c |  4 ++++
>  drivers/media/platform/qcom/iris/iris_vpu2.c       |  1 +
>  drivers/media/platform/qcom/iris/iris_vpu3x.c      |  9 +++-----
>  drivers/media/platform/qcom/iris/iris_vpu4x.c      | 24 ++++++++++++----------
>  drivers/media/platform/qcom/iris/iris_vpu_common.c | 16 +++++++++------
>  drivers/media/platform/qcom/iris/iris_vpu_common.h |  3 +++
>  7 files changed, 38 insertions(+), 23 deletions(-)
> 

Reviewed-by: Dikshita Agarwal <dikshita.agarwal@oss.qualcomm.com>

Thanks,
Dikshita