The order in which 'users' counter is decremented vs calling drivers' close() method is implementation specific, and we should not rely on it. Let's introduce driver private flag and use it to signal ISR to exit when device is being closed.
This has a side-effect of fixing issue of accessing inut->users outside of input->mutex protection. Reported-by: Andrzej Pietrasiewicz <[email protected]> Acked-by: Krzysztof Kozlowski <[email protected]> Reviewed-by: Michał Mirosław <[email protected]> Signed-off-by: Dmitry Torokhov <[email protected]> --- v3: fixed typo in exynos_adc_ts_close() per Michał Mirosław v2: switched from ordinary read/write to READ_ONCE/WRITE_ONCE per Michał Mirosław drivers/iio/adc/exynos_adc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c index 22131a677445..908df4b9b93c 100644 --- a/drivers/iio/adc/exynos_adc.c +++ b/drivers/iio/adc/exynos_adc.c @@ -7,6 +7,7 @@ * Copyright (C) 2013 Naveen Krishna Chatradhi <[email protected]> */ +#include <linux/compiler.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/interrupt.h> @@ -135,6 +136,8 @@ struct exynos_adc { u32 value; unsigned int version; + bool ts_enabled; + bool read_ts; u32 ts_x; u32 ts_y; @@ -633,7 +636,7 @@ static irqreturn_t exynos_ts_isr(int irq, void *dev_id) bool pressed; int ret; - while (info->input->users) { + while (READ_ONCE(info->ts_enabled)) { ret = exynos_read_s3c64xx_ts(dev, &x, &y); if (ret == -ETIMEDOUT) break; @@ -712,6 +715,7 @@ static int exynos_adc_ts_open(struct input_dev *dev) { struct exynos_adc *info = input_get_drvdata(dev); + WRITE_ONCE(info->ts_enabled, true); enable_irq(info->tsirq); return 0; @@ -721,6 +725,7 @@ static void exynos_adc_ts_close(struct input_dev *dev) { struct exynos_adc *info = input_get_drvdata(dev); + WRITE_ONCE(info->ts_enabled, false); disable_irq(info->tsirq); } -- 2.28.0.806.g8561365e88-goog -- Dmitry
