[PATCH v4 0/3] Add Equalization Settings for 8.0 GT/s and Add PCIe Lane Equalization Preset Properties for 8.0 GT/s and 16.0 GT/s

[Ziyue Zhang]

This series adds add equalization settings for 8.0 GT/s, and add PCIe lane equalization
preset properties for 8.0 GT/s and 16.0 GT/s for sa8775p ride platform, which fix AER
errors.

While equalization settings for 16 GT/s have already been set, this update adds the
required equalization settings for PCIe operating at 8.0 GT/s, including the
configuration of shadow registers, ensuring optimal performance and stability.

The DT change for sa8775p add PCIe lane equalization preset properties for 8 GT/s
and 16 GT/s data rates used in lane equalization procedure.

Signed-off-by: Ziyue Zhang <ziyue.zhang at oss.qualcomm.com>

Changes in v4:
- Bail out early if the link speed > 16 GT/s and use pci->max_link_speed directly (Mani)
- Fix the build warning. (Bjorn)
- Link to v3: https://lore.kernel.org/all/8ccd3731-8dbc-4972-a79a-ba78e90ec4a8@quicinc.com/

Changes in v3:
- Delte TODO tag and warn print in pcie-qcom-common.c. (Bjorn)
- Refined the commit message for better readability. (Bjorn)
- Link to v2: https://lore.kernel.org/all/20250611100319.464803-1-quic_ziyuzhan@quicinc.com/

Changes in v2:
- Update code in pcie-qcom-common.c make it easier to read. (Neil)
- Fix the compile error.
- Link to v1: https://lore.kernel.org/all/20250604091946.1890602-1-quic_ziyuzhan@quicinc.com


Ziyue Zhang (3):
  PCI: qcom: Add equalization settings for 8.0 GT/s
  PCI: qcom: fix macro typo for CURSOR
  arm64: dts: qcom: sa8775p: Add PCIe lane equalization preset
    properties

 arch/arm64/boot/dts/qcom/sa8775p.dtsi         |  6 +++
 drivers/pci/controller/dwc/pcie-designware.h  |  5 +-
 drivers/pci/controller/dwc/pcie-qcom-common.c | 54 ++++++++++---------
 drivers/pci/controller/dwc/pcie-qcom-common.h |  2 +-
 drivers/pci/controller/dwc/pcie-qcom-ep.c     |  6 +--
 drivers/pci/controller/dwc/pcie-qcom.c        |  6 +--
 6 files changed, 45 insertions(+), 34 deletions(-)


base-commit: 58ba80c4740212c29a1cf9b48f588e60a7612209
-- 
2.34.1