On Wed, Aug 20, 2025 at 01:58:46PM +0530, Krishna Chaitanya Chundru wrote: > 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@xxxxxxxxxxxxxxxx> > --- > Changes in v4: > - Included dtsi changes for all platforms. > - Made the changes as requested by Viresh like adding comments, some > coding styles etc. > - Link to v3: https://lore.kernel.org/r/20250819-opp_pcie-v3-0-f8bd7e05ce41@xxxxxxxxxxxxxxxx > > 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@xxxxxxxxxxxxxxxx > > 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@xxxxxxxxxxxxxxxx > > --- > Krishna Chaitanya Chundru (7): > OPP: Add support to find OPP for a set of keys > OPP: Move refcount and key update for readability in _opp_table_find_key() Hi Krishna, Patch 2/7 is applied in linux-next (20250825) as commit b5323835f050 (OPP: Reorganize _opp_table_find_key()) which is causing regression on my board (lemans-evk (arm64)). Reverting the change is resolving the issue. Kernel log: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000016 ... Call trace: _read_bw+0x0/0x10 (P) _find_key+0xb8/0x194 dev_pm_opp_find_bw_floor+0x54/0x8c bwmon_intr_thread+0x84/0x284 [icc_bwmon] irq_thread_fn+0x2c/0xa8 irq_thread+0x174/0x334 kthread+0x134/0x208 ret_from_fork+0x10/0x20 > arm64: dts: qcom: sm8450: Add opp-level to indicate PCIe data rates > arm64: dts: qcom: sm8550: Add opp-level to indicate PCIe data rates > arm64: dts: qcom: sm8650: Add opp-level to indicate PCIe data rates > arm64: dts: qcom: x1e80100: 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 ++++++++++--- > arch/arm64/boot/dts/qcom/sm8550.dtsi | 63 ++++++++++++++----- > arch/arm64/boot/dts/qcom/sm8650.dtsi | 63 ++++++++++++++----- > arch/arm64/boot/dts/qcom/x1e80100.dtsi | 90 ++++++++++++++++++++++----- > drivers/opp/core.c | 107 +++++++++++++++++++++++++++++++-- > drivers/pci/controller/dwc/pcie-qcom.c | 7 ++- > include/linux/pm_opp.h | 30 +++++++++ > 7 files changed, 341 insertions(+), 60 deletions(-) > --- > base-commit: c17b750b3ad9f45f2b6f7e6f7f4679844244f0b9 > change-id: 20250717-opp_pcie-793160b2b113 > > Best regards, > -- > Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx> > -- Regards, Wasim
