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spi_nxp_lpspi: Prevent edge case causing DMA error

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Stop the transfer with error if at any point there is some
execution reached where transfer is being set up for 0 length, this can
cause problems where for example eDMA set up with this nonsense 0 length
channels can get an infinite error interrupt.

And this is probably an erroneously crafted transfer request anyways.

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>
This commit is contained in:
Declan Snyder 2025-03-27 17:02:38 -05:00 • committed by Benjamin Cabé
commit 5acee4ad9d
1 changed files with 13 additions and 1 deletions
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14
drivers/spi/spi_nxp_lpspi/spi_nxp_lpspi_dma.c
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@ -102,6 +102,14 @@ static inline int spi_mcux_dma_rxtx_load(const struct device *dev)
size_t next_chunk_size = spi_context_max_continuous_chunk(ctx);
int ret = 0;
if (next_chunk_size == 0) {
/* In case both buffers are 0 length, we should not even be here
* and attempting to set up a DMA transfer like this will cause
* errors that lock up the system in some cases with eDMA.
*/
return -ENODATA;
}
ret = spi_mcux_dma_tx_load(dev, ctx->tx_buf, next_chunk_size);
if (ret != 0) {
return ret;
@ -223,7 +231,11 @@ static int transceive_dma(const struct device *dev, const struct spi_config *spi
spi_context_cs_control(ctx, true);
ret = spi_mcux_dma_next_fill(dev);
if (ret) {
if (ret == -ENODATA) {
/* No transfer to do? So just exit */
ret = 0;
goto out;
} else if (ret) {
goto out;
}