From 4edab7b08783f06679de0d24318d92ffc1dfd537 Mon Sep 17 00:00:00 2001 From: Petre Rodan Date: Wed, 14 Jan 2026 18:55:39 +0200 Subject: [PATCH] iio: pressure: mprls0025pa: move memset to core Move memset() from the bus specific code into core. Zeroing out the buffer is performed because the sensor has noticeable latch-up sensitivity and in some cases it clamps the MISO signal to GND in sync with SCLK [1]. A raw conversion of zero is out of bounds since valid values have to be between output_min and output_max (and the smallest output_min is 2.5% of 2^24 = 419430). The user is expected to discard out of bounds pressure values. Given the fact that we can't follow the behaviour of all SPI controllers when faced to this clamping of an output signal, a raw conversion of zero is used as an early warning in case the low level SPI API reacts unexpectedly. Link: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1588325/am3358-spi-tx-data-corruption [1] Signed-off-by: Petre Rodan Reviewed-by: Andy Shevchenko Signed-off-by: Jonathan Cameron --- drivers/iio/pressure/mprls0025pa.c | 2 ++ drivers/iio/pressure/mprls0025pa_i2c.c | 1 - 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iio/pressure/mprls0025pa.c b/drivers/iio/pressure/mprls0025pa.c index 2bcd339dc84e..a7041a503bde 100644 --- a/drivers/iio/pressure/mprls0025pa.c +++ b/drivers/iio/pressure/mprls0025pa.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -247,6 +248,7 @@ static int mpr_read_pressure(struct mpr_data *data, s32 *press) } } + memset(data->rx_buf, 0, sizeof(data->rx_buf)); ret = data->ops->read(data, MPR_CMD_NOP, MPR_PKT_NOP_LEN); if (ret < 0) return ret; diff --git a/drivers/iio/pressure/mprls0025pa_i2c.c b/drivers/iio/pressure/mprls0025pa_i2c.c index a0bbc6af9283..0fe8cfe0d7e7 100644 --- a/drivers/iio/pressure/mprls0025pa_i2c.c +++ b/drivers/iio/pressure/mprls0025pa_i2c.c @@ -25,7 +25,6 @@ static int mpr_i2c_read(struct mpr_data *data, const u8 unused, const u8 cnt) if (cnt > MPR_MEASUREMENT_RD_SIZE) return -EOVERFLOW; - memset(data->rx_buf, 0, MPR_MEASUREMENT_RD_SIZE); ret = i2c_master_recv(client, data->rx_buf, cnt); if (ret < 0) return ret; -- 2.47.3