hwmon: rp1-adc: fix spinlock leak on errors - #7656
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rp1_adc_read() returns with the spinlock held when the ADC is not ready in time or reports a conversion error. The next read then spins on the lock forever with preemption disabled. This also happens when RP1 stops responding on PCIe, since CS then reads as all ones with both READY and ERR set. Fixes: 512bbbd ("hwmon: Add RP1 ADC and temperature driver") Link: raspberrypi#7653 Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>
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September 28, 2026 12:33
pelwell
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kernel: ASoC: iqaudio-codec: Add mic-only start-up delay See: raspberrypi/linux#7535 kernel: configs: Enable CONFIG_DRM_PANIC See: raspberrypi/linux#7637 kernel: drm/vc4: fix two phase errors in the HVS scaler, and the chroma siting default See: raspberrypi/linux#7630 kernel: Make the MXL86110 LEDs emulate the BCM54210 See: raspberrypi/linux#7640 kernel: Starvis2 sensor driver support (IMX662) See: raspberrypi/linux#7615 kernel: media: i2c: arducam_64mp: Fix crop sizes for 9152x6944 and 8000x6000 See: raspberrypi/linux#7652 kernel: hwmon: rp1-adc: fix spinlock leak on errors See: raspberrypi/linux#7656 kernel: media: sony-starvis2: Correct the minimum exposure See: raspberrypi/linux#7658 kernel: overlays: i2c-rtc: Add quartz-load-femtofarads See: raspberrypi/linux#7660 kernel: dmaengine: dw-axi-dmac: Add channel abort support See: raspberrypi/linux#7654
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kernel: ASoC: iqaudio-codec: Add mic-only start-up delay See: raspberrypi/linux#7535 kernel: configs: Enable CONFIG_DRM_PANIC See: raspberrypi/linux#7637 kernel: drm/vc4: fix two phase errors in the HVS scaler, and the chroma siting default See: raspberrypi/linux#7630 kernel: Make the MXL86110 LEDs emulate the BCM54210 See: raspberrypi/linux#7640 kernel: Starvis2 sensor driver support (IMX662) See: raspberrypi/linux#7615 kernel: media: i2c: arducam_64mp: Fix crop sizes for 9152x6944 and 8000x6000 See: raspberrypi/linux#7652 kernel: hwmon: rp1-adc: fix spinlock leak on errors See: raspberrypi/linux#7656 kernel: media: sony-starvis2: Correct the minimum exposure See: raspberrypi/linux#7658 kernel: overlays: i2c-rtc: Add quartz-load-femtofarads See: raspberrypi/linux#7660 kernel: dmaengine: dw-axi-dmac: Add channel abort support See: raspberrypi/linux#7654
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rp1_adc_read() returns with the spinlock held when the ADC is not ready in time or reports a conversion error. The next read then spins on the lock forever with preemption disabled.
This also happens when RP1 stops responding on PCIe, since CS then reads as all ones with both READY and ERR set.
Fixes: 512bbbd ("hwmon: Add RP1 ADC and temperature driver")
Link: #7653