drivers: adc: esp32: fix oneshot read hang with wi-fi power save - #117346
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drivers: adc: esp32: fix oneshot read hang with wi-fi power save#117346sylvioalves wants to merge 2 commits into
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The oneshot read path touched the analog calibration registers and started conversions without holding the analog i2c master clock. On SoCs where that clock is root gated it is shared with the Wi-Fi modem, so the first modem sleep cycle gated it and the conversion polling never returned. Hold the reference counted analog clock across channel setup, calibration load and conversion, and propagate a conversion failure as -ETIMEDOUT so callers can retry when the shared analog hardware is temporarily powered down by modem sleep. The completion wait bound is adjustable through the new ADC_ESP32_CONVERSION_TIMEOUT_US option. Assisted-by: Claude:opus-4-8 Signed-off-by: Sylvio Alves <sylvio.alves@espressif.com>
The continuous acquisition path programs the analog calibration registers and runs the shared front-end without holding the analog i2c master clock, the same gap the oneshot path had. Hold the reference counted clock from controller start until stop so the acquisition does not depend on another user keeping that clock enabled. Assisted-by: Claude:opus-4-8 Signed-off-by: Sylvio Alves <sylvio.alves@espressif.com>
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August 25, 2026 19:30
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When Wi-Fi power saving is enabled, adc_read() can hang forever because the ADC shares an analog clock with the Wi-Fi modem and the hal waits for the conversion result in a loop with no timeout. While the modem sleeps the conversion can never finish.
The driver now holds the analog clock while reading and the hal wait is bounded, so instead of hanging the read returns ETIMEDOUT and the application can simply retry. The timeout is configurable through ADC_ESP32_CONVERSION_TIMEOUT_US.
Fixes #117247