This is a note to let you know that I've just added the patch titled
iio: adc: at91-sama5d2_adc: fix channel configuration for
to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From f0c8d1f6dc8eac5a1fbf441c8e080721a7b6c0ff Mon Sep 17 00:00:00 2001
From: Eugen Hristev eugen.hristev@microchip.com Date: Tue, 10 Apr 2018 11:57:47 +0300 Subject: iio: adc: at91-sama5d2_adc: fix channel configuration for differential channels
When iterating through the channels, the index in the array is not the scan index. Added an xlate function to translate to the proper index. The result of the bug is that the channel array is indexed with a wrong index, thus instead of the proper channel, we access invalid memory, which may lead to invalid results and/or corruption. This will be used also for devicetree channel xlate.
Fixes: 5e1a1da0f ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support") Fixes: 073c66201 ("iio: adc: at91-sama5d2_adc: add support for DMA") Signed-off-by: Eugen Hristev eugen.hristev@microchip.com Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com --- drivers/iio/adc/at91-sama5d2_adc.c | 41 +++++++++++++++++++++++++++--- 1 file changed, 37 insertions(+), 4 deletions(-)
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c index 4eff8351ce29..8729d6524b4d 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -333,6 +333,27 @@ static const struct iio_chan_spec at91_adc_channels[] = { + AT91_SAMA5D2_DIFF_CHAN_CNT + 1), };
+static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan) +{ + int i; + + for (i = 0; i < indio_dev->num_channels; i++) { + if (indio_dev->channels[i].scan_index == chan) + return i; + } + return -EINVAL; +} + +static inline struct iio_chan_spec const * +at91_adc_chan_get(struct iio_dev *indio_dev, int chan) +{ + int index = at91_adc_chan_xlate(indio_dev, chan); + + if (index < 0) + return NULL; + return indio_dev->channels + index; +} + static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state) { struct iio_dev *indio = iio_trigger_get_drvdata(trig); @@ -350,8 +371,10 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state) at91_adc_writel(st, AT91_SAMA5D2_TRGR, status);
for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) { - struct iio_chan_spec const *chan = indio->channels + bit; + struct iio_chan_spec const *chan = at91_adc_chan_get(indio, bit);
+ if (!chan) + continue; if (state) { at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel)); @@ -448,7 +471,11 @@ static int at91_adc_dma_start(struct iio_dev *indio_dev)
for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->num_channels) { - struct iio_chan_spec const *chan = indio_dev->channels + bit; + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit); + + if (!chan) + continue;
st->dma_st.rx_buf_sz += chan->scan_type.storagebits / 8; } @@ -526,8 +553,11 @@ static int at91_adc_buffer_predisable(struct iio_dev *indio_dev) */ for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->num_channels) { - struct iio_chan_spec const *chan = indio_dev->channels + bit; + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit);
+ if (!chan) + continue; if (st->dma_st.dma_chan) at91_adc_readl(st, chan->address); } @@ -587,8 +617,11 @@ static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->num_channels) { - struct iio_chan_spec const *chan = indio_dev->channels + bit; + struct iio_chan_spec const *chan = + at91_adc_chan_get(indio_dev, bit);
+ if (!chan) + continue; st->buffer[i] = at91_adc_readl(st, chan->address); i++; }