From: Claudiu Beznea <claudiu.beznea@microchip.com> To: <eugen.hristev@microchip.com>, <jic23@kernel.org>, <lars@metafoo.de>, <nicolas.ferre@microchip.com>, <alexandre.belloni@bootlin.com>, <ludovic.desroches@microchip.com>, <robh+dt@kernel.org> Cc: <linux-iio@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>, Claudiu Beznea <claudiu.beznea@microchip.com> Subject: [PATCH v3 03/19] iio: adc: at91-sama5d2_adc: lock around oversampling and sample freq Date: Wed, 3 Aug 2022 13:28:39 +0300 [thread overview] Message-ID: <20220803102855.2191070-4-claudiu.beznea@microchip.com> (raw) In-Reply-To: <20220803102855.2191070-1-claudiu.beznea@microchip.com> .read_raw()/.write_raw() could be called asynchronously from user space or other in kernel drivers. Without locking on st->lock these could be called asynchronously while there is a conversion in progress. Read will be harmless but changing registers while conversion is in progress may lead to inconsistent results. Thus, to avoid this lock st->lock. Fixes: 27e177190891 ("iio:adc:at91_adc8xx: introduce new atmel adc driver") Fixes: 6794e23fa3fe ("iio: adc: at91-sama5d2_adc: add support for oversampling resolution") Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> --- drivers/iio/adc/at91-sama5d2_adc.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index 08d1f806c839..3734ddc82952 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -1542,10 +1542,10 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev, ret = at91_adc_read_position(st, chan->channel, &tmp_val); *val = tmp_val; - mutex_unlock(&st->lock); - iio_device_release_direct_mode(indio_dev); if (ret > 0) ret = at91_adc_adjust_val_osr(st, val); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); return ret; } @@ -1558,10 +1558,10 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev, ret = at91_adc_read_pressure(st, chan->channel, &tmp_val); *val = tmp_val; - mutex_unlock(&st->lock); - iio_device_release_direct_mode(indio_dev); if (ret > 0) ret = at91_adc_adjust_val_osr(st, val); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); return ret; } @@ -1650,16 +1650,20 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, /* if no change, optimize out */ if (val == st->oversampling_ratio) return 0; + mutex_lock(&st->lock); st->oversampling_ratio = val; /* update ratio */ at91_adc_config_emr(st); + mutex_unlock(&st->lock); return 0; case IIO_CHAN_INFO_SAMP_FREQ: if (val < st->soc_info.min_sample_rate || val > st->soc_info.max_sample_rate) return -EINVAL; + mutex_lock(&st->lock); at91_adc_setup_samp_freq(indio_dev, val); + mutex_unlock(&st->lock); return 0; default: return -EINVAL; -- 2.34.1
WARNING: multiple messages have this Message-ID (diff)
From: Claudiu Beznea <claudiu.beznea@microchip.com> To: <eugen.hristev@microchip.com>, <jic23@kernel.org>, <lars@metafoo.de>, <nicolas.ferre@microchip.com>, <alexandre.belloni@bootlin.com>, <ludovic.desroches@microchip.com>, <robh+dt@kernel.org> Cc: <linux-iio@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>, Claudiu Beznea <claudiu.beznea@microchip.com> Subject: [PATCH v3 03/19] iio: adc: at91-sama5d2_adc: lock around oversampling and sample freq Date: Wed, 3 Aug 2022 13:28:39 +0300 [thread overview] Message-ID: <20220803102855.2191070-4-claudiu.beznea@microchip.com> (raw) In-Reply-To: <20220803102855.2191070-1-claudiu.beznea@microchip.com> .read_raw()/.write_raw() could be called asynchronously from user space or other in kernel drivers. Without locking on st->lock these could be called asynchronously while there is a conversion in progress. Read will be harmless but changing registers while conversion is in progress may lead to inconsistent results. Thus, to avoid this lock st->lock. Fixes: 27e177190891 ("iio:adc:at91_adc8xx: introduce new atmel adc driver") Fixes: 6794e23fa3fe ("iio: adc: at91-sama5d2_adc: add support for oversampling resolution") Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> --- drivers/iio/adc/at91-sama5d2_adc.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index 08d1f806c839..3734ddc82952 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -1542,10 +1542,10 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev, ret = at91_adc_read_position(st, chan->channel, &tmp_val); *val = tmp_val; - mutex_unlock(&st->lock); - iio_device_release_direct_mode(indio_dev); if (ret > 0) ret = at91_adc_adjust_val_osr(st, val); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); return ret; } @@ -1558,10 +1558,10 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev, ret = at91_adc_read_pressure(st, chan->channel, &tmp_val); *val = tmp_val; - mutex_unlock(&st->lock); - iio_device_release_direct_mode(indio_dev); if (ret > 0) ret = at91_adc_adjust_val_osr(st, val); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); return ret; } @@ -1650,16 +1650,20 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, /* if no change, optimize out */ if (val == st->oversampling_ratio) return 0; + mutex_lock(&st->lock); st->oversampling_ratio = val; /* update ratio */ at91_adc_config_emr(st); + mutex_unlock(&st->lock); return 0; case IIO_CHAN_INFO_SAMP_FREQ: if (val < st->soc_info.min_sample_rate || val > st->soc_info.max_sample_rate) return -EINVAL; + mutex_lock(&st->lock); at91_adc_setup_samp_freq(indio_dev, val); + mutex_unlock(&st->lock); return 0; default: return -EINVAL; -- 2.34.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-08-03 10:27 UTC|newest] Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-08-03 10:28 [PATCH v3 00/19] iio: adc: at91-sama5d2_adc: add support for temperature sensor Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 01/19] iio: adc: at91-sama5d2_adc: fix AT91_SAMA5D2_MR_TRACKTIM_MAX Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 02/19] iio: adc: at91-sama5d2_adc: check return status for pressure and touch Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea [this message] 2022-08-03 10:28 ` [PATCH v3 03/19] iio: adc: at91-sama5d2_adc: lock around oversampling and sample freq Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 04/19] iio: adc: at91-sama5d2_adc: disable/prepare buffer on suspend/resume Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 05/19] iio: adc: at91-sama5d2_adc: exit from write_raw() when buffers are enabled Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 06/19] iio: adc: at91-sama5d2_adc: handle different EMR.OSR for different hw versions Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 07/19] iio: adc: at91-sama5d2_adc: move the check of oversampling in its function Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 08/19] iio: adc: at91-sama5d2_adc: drop AT91_OSR_XSAMPLES defines Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 09/19] iio: adc: at91-sama5d2_adc: add .read_avail() chan_info ops Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 10/19] iio: adc: at91-sama5d2_adc: adjust osr based on specific platform data Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 11/19] iio: adc: at91-sama5d2_adc: add 64 and 256 oversampling ratio Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 12/19] iio: adc: at91-sama5d2_adc: move oversampling storage in its function Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 13/19] iio: adc: at91-sama5d2_adc: update trackx on emr Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 14/19] iio: adc: at91-sama5d2_adc: add startup and tracktim as parameter for at91_adc_setup_samp_freq() Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 15/19] iio: adc: at91-sama5d2_adc: lock around at91_adc_read_info_raw() Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 16/19] dt-bindings: iio: adc: at91-sama5d2_adc: add id for temperature channel Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 17/19] iio: adc: at91-sama5d2_adc: add support for temperature sensor Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 18/19] iio: adc: at91-sama5d2_adc: add empty line after functions Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-03 10:28 ` [PATCH v3 19/19] iio: adc: at91-sama5d2_adc: add runtime pm support Claudiu Beznea 2022-08-03 10:28 ` Claudiu Beznea 2022-08-06 14:10 ` [PATCH v3 00/19] iio: adc: at91-sama5d2_adc: add support for temperature sensor Jonathan Cameron 2022-08-06 14:10 ` Jonathan Cameron
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