[PATCH 0/4] Retrieve information about DDR from SMEM

[Dmitry Baryshkov]

On 09/04/2025 17:47, Konrad Dybcio wrote:
> SMEM allows the OS to retrieve information about the DDR memory.
> Among that information, is a semi-magic value called 'HBB', or Highest
> Bank address Bit, which multimedia drivers (for hardware like Adreno
> and MDSS) must retrieve in order to program the IP blocks correctly.
> 
> This series introduces an API to retrieve that value, uses it in the
> aforementioned programming sequences and exposes available DDR
> frequencies in debugfs (to e.g. pass to aoss_qmp debugfs). More
> information can be exposed in the future, as needed.

I know that for some platforms HBB differs between GPU and DPU (as it's 
being programmed currently). Is there a way to check, which values are 
we going to program:

- SM6115, SM6350, SM6375 (13 vs 14)
- SC8180X (15 vs 16)
- QCM2290 (14 vs 15)


> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio at oss.qualcomm.com>
> ---
> Konrad Dybcio (4):
>        soc: qcom: Expose DDR data from SMEM
>        drm/msm/a5xx: Get HBB dynamically, if available
>        drm/msm/a6xx: Get HBB dynamically, if available
>        drm/msm/mdss: Get HBB dynamically, if available
> 
>   drivers/gpu/drm/msm/adreno/a5xx_gpu.c |  13 +-
>   drivers/gpu/drm/msm/adreno/a6xx_gpu.c |  22 ++-
>   drivers/gpu/drm/msm/msm_mdss.c        |  35 ++++-
>   drivers/soc/qcom/Makefile             |   3 +-
>   drivers/soc/qcom/smem.c               |  14 +-
>   drivers/soc/qcom/smem.h               |   9 ++
>   drivers/soc/qcom/smem_dramc.c         | 287 ++++++++++++++++++++++++++++++++++
>   include/linux/soc/qcom/smem.h         |   4 +
>   8 files changed, 371 insertions(+), 16 deletions(-)
> ---
> base-commit: 46086739de22d72319e37c37a134d32db52e1c5c
> change-id: 20250409-topic-smem_dramc-6467187ac865
> 
> Best regards,


-- 
With best wishes
Dmitry