iio: adc: ti-adc108s102: Fix alignment of buffer pushed to iio buffers.

Use the newly introduce iio_push_to_buffers_with_ts_unaligned() function
to ensure a bounce buffer is used to provide the required alignment and
space padding needed by the IIO core which requires the timestamp
is naturally aligned.  There will be a performance cost to this change
but it will ensure the driver works on platforms that do not support
unaligned 8 byte assignments, and with consumer drivers that may
assume natural alignment of the timestamp.

Issue found as part of an audit of all calls to
iio_push_to_buffers_with_timestamp()

Fixes: 7e87d11c9bda ("iio: adc: Add support for TI ADC108S102 and ADC128S102")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Link: https://lore.kernel.org/r/20210613151039.569883-3-jic23@kernel.org

diff --git a/drivers/iio/adc/ti-adc108s102.c b/drivers/iio/adc/ti-adc108s102.c
index db902ae..c8e4888 100644 (file)
--- a/drivers/iio/adc/ti-adc108s102.c
+++ b/drivers/iio/adc/ti-adc108s102.c
@@ -75,9 +75,9 @@ struct adc108s102_state {
         *  rx_buf: |XX|R0|R1|R2|R3|R4|R5|R6|R7|tt|tt|tt|tt|
         *
         *  tx_buf: 8 channel read commands, plus 1 dummy command
-        *  rx_buf: 1 dummy response, 8 channel responses, plus 64-bit timestamp
+        *  rx_buf: 1 dummy response, 8 channel responses
         */
-       __be16                          rx_buf[13] ____cacheline_aligned;
+       __be16                          rx_buf[9] ____cacheline_aligned;
        __be16                          tx_buf[9] ____cacheline_aligned;
 };
 
@@ -149,9 +149,10 @@ static irqreturn_t adc108s102_trigger_handler(int irq, void *p)
                goto out_notify;
 
        /* Skip the dummy response in the first slot */
-       iio_push_to_buffers_with_timestamp(indio_dev,
-                                          (u8 *)&st->rx_buf[1],
-                                          iio_get_time_ns(indio_dev));
+       iio_push_to_buffers_with_ts_unaligned(indio_dev,
+                                             &st->rx_buf[1],
+                                             st->ring_xfer.len - sizeof(st->rx_buf[1]),
+                                             iio_get_time_ns(indio_dev));
 
 out_notify:
        iio_trigger_notify_done(indio_dev->trig);