The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 40c48fb79b9798954691f24b8ece1d3a7eb1b353 Mon Sep 17 00:00:00 2001
From: Lorenzo Bianconi lorenzo@kernel.org Date: Tue, 8 Dec 2020 15:36:40 +0100 Subject: [PATCH] iio: common: st_sensors: fix possible infinite loop in st_sensors_irq_thread
Return a boolean value in st_sensors_new_samples_available routine in order to avoid an infinite loop in st_sensors_irq_thread if stat_drdy.addr is not defined or stat_drdy read fails
Fixes: 90efe05562921 ("iio: st_sensors: harden interrupt handling") Reported-by: Jonathan Cameron jic23@kernel.org Signed-off-by: Lorenzo Bianconi lorenzo@kernel.org Reviewed-by: Linus Walleij linus.walleij@linaro.org Link: https://lore.kernel.org/r/c9ec69ed349e7200c779fd7a5bf04c1aaa2817aa.160743813... Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com
diff --git a/drivers/iio/common/st_sensors/st_sensors_trigger.c b/drivers/iio/common/st_sensors/st_sensors_trigger.c index 0507283bd4c1..2dbd2646e44e 100644 --- a/drivers/iio/common/st_sensors/st_sensors_trigger.c +++ b/drivers/iio/common/st_sensors/st_sensors_trigger.c @@ -23,35 +23,31 @@ * @sdata: Sensor data. * * returns: - * 0 - no new samples available - * 1 - new samples available - * negative - error or unknown + * false - no new samples available or read error + * true - new samples available */ -static int st_sensors_new_samples_available(struct iio_dev *indio_dev, - struct st_sensor_data *sdata) +static bool st_sensors_new_samples_available(struct iio_dev *indio_dev, + struct st_sensor_data *sdata) { int ret, status;
/* How would I know if I can't check it? */ if (!sdata->sensor_settings->drdy_irq.stat_drdy.addr) - return -EINVAL; + return true;
/* No scan mask, no interrupt */ if (!indio_dev->active_scan_mask) - return 0; + return false;
ret = regmap_read(sdata->regmap, sdata->sensor_settings->drdy_irq.stat_drdy.addr, &status); if (ret < 0) { dev_err(sdata->dev, "error checking samples available\n"); - return ret; + return false; }
- if (status & sdata->sensor_settings->drdy_irq.stat_drdy.mask) - return 1; - - return 0; + return !!(status & sdata->sensor_settings->drdy_irq.stat_drdy.mask); }
/** @@ -180,9 +176,15 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
/* Tell the interrupt handler that we're dealing with edges */ if (irq_trig == IRQF_TRIGGER_FALLING || - irq_trig == IRQF_TRIGGER_RISING) + irq_trig == IRQF_TRIGGER_RISING) { + if (!sdata->sensor_settings->drdy_irq.stat_drdy.addr) { + dev_err(&indio_dev->dev, + "edge IRQ not supported w/o stat register.\n"); + err = -EOPNOTSUPP; + goto iio_trigger_free; + } sdata->edge_irq = true; - else + } else { /* * If we're not using edges (i.e. level interrupts) we * just mask off the IRQ, handle one interrupt, then @@ -190,6 +192,7 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev, * interrupt handler top half again and start over. */ irq_trig |= IRQF_ONESHOT; + }
/* * If the interrupt pin is Open Drain, by definition this