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

Konrad Dybcio konradybcio at kernel.org
Wed Apr 9 14:47:28 UTC 2025


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.

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,
-- 
Konrad Dybcio <konrad.dybcio at oss.qualcomm.com>



More information about the Freedreno mailing list