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From: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
To: "Viresh Kumar" <vireshk@kernel.org>, "Nishanth Menon" <nm@ti.com>,
	"Stephen Boyd" <sboyd@kernel.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	"Manivannan Sadhasivam" <mani@kernel.org>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
	"Rob Herring" <robh@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Bjorn Andersson" <andersson@kernel.org>,
	"Konrad Dybcio" <konradybcio@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-pci@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	devicetree@vger.kernel.org,
	Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
Subject: [PATCH v3 0/3] OPP: Add support to find OPP for a set of keys
Date: Tue, 19 Aug 2025 11:04:41 +0530	[thread overview]
Message-ID: <20250819-opp_pcie-v3-0-f8bd7e05ce41@oss.qualcomm.com> (raw)

The existing OPP table in the device tree for PCIe is shared across
different link configurations such as data rates 8GT/s x2 and 16GT/s x1.
These configurations often operate at the same frequency, allowing them
to reuse the same OPP entries. However, 8GT/s and 16 GT/s may have
different characteristics beyond frequency—such as RPMh votes in QCOM
case, which cannot be represented accurately when sharing a single OPP.

In such cases, frequency alone is not sufficient to uniquely identify
an OPP. To support these scenarios, introduce a new API
dev_pm_opp_find_key_exact() that allows OPP lookup for set of keys like
frequency, level & bandwidth.

Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
---
Changes in v3:
- Always check for frequency match unless user doesn't pass it (Viresh).
- Make dev_pm_opp_key public and let user pass the key (Viresh).
- Include bandwidth as part of dev_pm_opp_key (Viresh).
- Link to v2: https://lore.kernel.org/r/20250818-opp_pcie-v2-0-071524d98967@oss.qualcomm.com

Changes in v2:
- Use opp-level to indentify data rate and use both frequency and level
  to identify the OPP. (Viresh)
- Link to v1: https://lore.kernel.org/r/20250717-opp_pcie-v1-0-dde6f452571b@oss.qualcomm.com

---
Krishna Chaitanya Chundru (3):
      OPP: Add support to find OPP for a set of keys
      arm64: dts: qcom: sm8450: Add opp-level to indicate PCIe data rates
      PCI: qcom: Use frequency and level based OPP lookup

 arch/arm64/boot/dts/qcom/sm8450.dtsi   |  41 +++++++++++---
 drivers/opp/core.c                     | 100 +++++++++++++++++++++++++++++++++
 drivers/pci/controller/dwc/pcie-qcom.c |   6 +-
 include/linux/pm_opp.h                 |  23 ++++++++
 4 files changed, 160 insertions(+), 10 deletions(-)
---
base-commit: c17b750b3ad9f45f2b6f7e6f7f4679844244f0b9
change-id: 20250717-opp_pcie-793160b2b113

Best regards,
-- 
Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>


             reply	other threads:[~2025-08-19  5:34 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-08-19  5:34 Krishna Chaitanya Chundru [this message]
2025-08-19  5:34 ` [PATCH v3 1/3] OPP: Add support to find OPP for a set of keys Krishna Chaitanya Chundru
2025-08-19  8:18   ` Viresh Kumar
2025-08-20  4:27     ` Krishna Chaitanya Chundru
2025-08-19  5:34 ` [PATCH v3 2/3] arm64: dts: qcom: sm8450: Add opp-level to indicate PCIe data rates Krishna Chaitanya Chundru
2025-09-02 11:47   ` Konrad Dybcio
2025-08-19  5:34 ` [PATCH v3 3/3] PCI: qcom: Use frequency and level based OPP lookup Krishna Chaitanya Chundru

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