Re: [PATCH v8] crypto: qce - Add runtime PM and interconnect bandwidth scaling support

On 5/17/2026 4:22 PM, Udit Tiwari wrote:
> The Qualcomm Crypto Engine (QCE) driver currently lacks support for
> runtime power management (PM) and interconnect bandwidth control.
> As a result, the hardware remains fully powered and clocks stay
> enabled even when the device is idle. Additionally, static
> interconnect bandwidth votes are held indefinitely, preventing the
> system from reclaiming unused bandwidth.
> 
> Address this by enabling runtime PM and dynamic interconnect
> bandwidth scaling to allow the system to suspend the device when idle
> and scale interconnect usage based on actual demand. Improve overall
> system efficiency by reducing power usage and optimizing interconnect
> resource allocation.
> 
> Signed-off-by: Udit Tiwari <[email protected]>
> ---
Checked interconnect vote summary while triggering s2idle and resume

Tested-by: Pankaj Patil <[email protected]>

> Tested:
> 
> - Verify that ICC votes drop to zero after probe and upon request
>   completion.
> - Confirm that runtime PM usage count increments during active
>   requests and decrements afterward.
> - Observe that the device correctly enters the suspended state when
>   idle.
> 
> Changes in v8:
> - Drop pm_clk framework (devm_pm_clk_create/pm_clk_add/pm_clk_suspend/
>   pm_clk_resume); use devm_clk_get_optional() and direct
>   clk_prepare_enable()/clk_disable_unprepare() in runtime PM callbacks.
>   This removes the CONFIG_PM_CLK dependency and the build error reported
>   by the kernel test robot.
> - Replace icc_disable() with icc_set_bw(path, 0, 0) in runtime suspend
>   to avoid corrupting the internal 'enabled' flag, which would cause
>   subsequent icc_set_bw() calls in resume to be silently skipped during
>   aggregation.
> - Fix ICC vote ordering: cast bandwidth vote before enabling clocks in
>   resume; disable clocks before dropping ICC vote in suspend.
> - Use PM_RUNTIME_ACQUIRE_AUTOSUSPEND()/PM_RUNTIME_ACQUIRE_ERR() wrapper
>   macros instead of raw ACQUIRE() in both qce_handle_queue() and probe.
> - Drop __maybe_unused from runtime PM callbacks; use RUNTIME_PM_OPS /
>   SYSTEM_SLEEP_PM_OPS (non-SET_ prefix) and pm_ptr(&qce_crypto_pm_ops).
> - Drop unnecessary ret = 0 initializations in qce_handle_queue() and
>   qce_runtime_resume().
> - Extend probe comment to explain ICC + clock ordering rationale.
> - Link to v7:
>   https://lore.kernel.org/lkml/[email protected]/
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