You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@nuttx.apache.org by ra...@apache.org on 2020/09/14 05:21:31 UTC
[incubator-nuttx] branch master updated: nrf52: SPI transfer
failure and corruption
This is an automated email from the ASF dual-hosted git repository.
raiden00 pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git
The following commit(s) were added to refs/heads/master by this push:
new 93eeecf nrf52: SPI transfer failure and corruption
93eeecf is described below
commit 93eeecff6ab5de1a9ab5593bbf556142d00f32c0
Author: Brennan Ashton <ba...@brennanashton.com>
AuthorDate: Sun Sep 13 15:43:57 2020 -0700
nrf52: SPI transfer failure and corruption
The current EasyDMA implementation will fail if a transfer of over
255 bytes is requested with no warning.
Also we do not set the RX and TX transfer lengths to 0 if the
buffer is NULL which can cause data to be written to the old
address as well as cause unexpected transaction lenghts.
Example:
transfer 1:
rx_len = 10
rx_buff != NULL
tx_len = 10
tx_buff != NULL
transfer 2:
rx_len = 2
rx_buff != NULL
tx_buff == NULL
Total transaction length for the second would be 10 because it
would still be using the old rx length of 10 and would
corrupt data in the old rx buffer.
Signed-off-by: Brennan Ashton <ba...@brennanashton.com>
---
arch/arm/src/nrf52/nrf52_spi.c | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/arch/arm/src/nrf52/nrf52_spi.c b/arch/arm/src/nrf52/nrf52_spi.c
index 3127ceb..12ad103 100644
--- a/arch/arm/src/nrf52/nrf52_spi.c
+++ b/arch/arm/src/nrf52/nrf52_spi.c
@@ -858,7 +858,7 @@ static void nrf52_spi_1b_workaround(FAR struct spi_dev_s *dev, bool enable)
* dev - Device-specific state data
* txbuffer - A pointer to the buffer of data to be sent
* rxbuffer - A pointer to a buffer in which to receive data
- * nwords - the length of data to be exchaned in units of words.
+ * nwords - the length of data to be exchanged in units of words.
* The wordsize is determined by the number of bits-per-word
* selected for the SPI interface.
*
@@ -874,6 +874,15 @@ static void nrf52_spi_exchange(FAR struct spi_dev_s *dev,
FAR struct nrf52_spidev_s *priv = (FAR struct nrf52_spidev_s *)dev;
uint32_t regval = 0;
+ if (nwords > 0xff)
+ {
+ /* MAXCNT register can only hold 8bits */
+
+ spierr("SPI transfer max of 255 bytes, %d requested\n")
+ DEBUGASSERT(false);
+ return;
+ }
+
#ifdef CONFIG_NRF52_SPI_MASTER_WORKAROUND_1BYTE_TRANSFER
if (nwords <= 1)
{
@@ -893,6 +902,10 @@ static void nrf52_spi_exchange(FAR struct spi_dev_s *dev,
regval = nwords;
nrf52_spi_putreg(priv, NRF52_SPIM_RXDMAXCNT_OFFSET, regval);
}
+ else
+ {
+ nrf52_spi_putreg(priv, NRF52_SPIM_RXDMAXCNT_OFFSET, 0);
+ }
if (txbuffer != NULL)
{
@@ -906,6 +919,10 @@ static void nrf52_spi_exchange(FAR struct spi_dev_s *dev,
regval = nwords;
nrf52_spi_putreg(priv, NRF52_SPIM_TXDMAXCNT_OFFSET, regval);
}
+ else
+ {
+ nrf52_spi_putreg(priv, NRF52_SPIM_TXDMAXCNT_OFFSET, 0);
+ }
/* SPI start */
@@ -925,6 +942,11 @@ static void nrf52_spi_exchange(FAR struct spi_dev_s *dev,
nxsem_wait(&priv->sem_isr);
#endif
+ if (nrf52_spi_getreg(priv, NRF52_SPIM_TXDAMOUNT_OFFSET) != nwords)
+ {
+ spierr("Incomplete transfer wrote %d expected %d\n", regval, nwords);
+ }
+
/* SPI stop */
nrf52_spi_putreg(priv, NRF52_SPIM_TASK_STOP_OFFSET, SPIM_TASKS_STOP);