[PATCH V3 0/4] Add DT-based gear and rate limiting support
From: Ram Kumar Dwivedi <hidden>
Date: 2025-08-26 15:09:33
Also in:
linux-arm-msm, linux-scsi, lkml
From: Ram Kumar Dwivedi <redacted> This patch series adds support for limiting the maximum high-speed gear and rate used by the UFS controller via device tree properties. Some platforms may have signal integrity, clock configuration, or layout issues that prevent reliable operation at higher gears or rates. This is especially critical in automotive and other platforms where stability is prioritized over peak performance. The series follows this logical progression: 1. Document the new DT properties in the common UFS binding 2. Clean up existing redundant code in the qcom driver 3. Add platform-level parsing support for the new properties 4. Integrate the platform support in the qcom driver This approach makes the functionality available to other UFS host drivers and provides a cleaner, more maintainable implementation. Changes from V1: - Restructured patch series for better logical flow and maintainability. - Moved DT bindings to ufs-common.yaml making it available for all UFS controllers. - Added platform-level support in ufshcd-pltfrm.c for code reusability. - Separated the cleanup patch to remove redundant hs_rate assignment in qcom driver. - Removed SA8155 DTS changes to keep the series focused on core functionality. - Improved commit messages with better technical rationale. Changes from V2: - Documented default values of limit-rate and limit-hs-gear in DT bindings as per Krzysztof's suggestion. Ram Kumar Dwivedi (4): ufs: dt-bindings: Document gear and rate limit properties ufs: ufs-qcom: Remove redundant re-assignment to hs_rate ufs: pltfrm: Allow limiting HS gear and rate via DT ufs: ufs-qcom: Add support for limiting HS gear and rate .../devicetree/bindings/ufs/ufs-common.yaml | 18 ++++++++++++ drivers/ufs/host/ufs-qcom.c | 21 ++++++++++---- drivers/ufs/host/ufshcd-pltfrm.c | 29 +++++++++++++++++++ drivers/ufs/host/ufshcd-pltfrm.h | 1 + 4 files changed, 63 insertions(+), 6 deletions(-) -- 2.50.1