From c5bf4d645f2d5c4c216dd690c5237d778102c848 Mon Sep 17 00:00:00 2001 From: "dmitry.torokhov@gmail.com" Date: Tue, 6 Oct 2020 14:55:09 -0700 Subject: [PATCH] iio: adc: exynos: do not rely on 'users' counter in ISR MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Dmitry Torokhov Reviewed-by: Michał Mirosław Acked-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20201006215509.GA2556081@dtor-ws Signed-off-by: Jonathan Cameron --- 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 99f4404e9fd1..784c10deeb1a 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 */ +#include #include #include #include @@ -135,6 +136,8 @@ struct exynos_adc { u32 value; unsigned int version; + bool ts_enabled; + bool read_ts; u32 ts_x; u32 ts_y; @@ -651,7 +654,7 @@ 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; @@ -731,6 +734,7 @@ 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; @@ -740,6 +744,7 @@ 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); }