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mimxrt: Compensate for a bug in the fsl_lpspi.c file.

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This library file has a bug, in that TransferBlocking returns before the
transfer has finished. That is a problem if a write follows immediately
a read.
This commit is contained in:
robert-hh 2021-12-27 13:46:56 +01:00 committed by Damien George
parent 84b76e4fbf
commit b8a0358c34
1 changed files with 5 additions and 1 deletions
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6
ports/mimxrt/machine_spi.c
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@ -230,7 +230,7 @@ void LPSPI_EDMAMasterCallback(LPSPI_Type *base, lpspi_master_edma_handle_t *hand
STATIC void machine_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8_t *src, uint8_t *dest) {
machine_spi_obj_t *self = (machine_spi_obj_t *)self_in;
// Use DMA for large transfers if channels are available
const size_t dma_min_size_threshold = 16; // That's the FIFO size
const size_t dma_min_size_threshold = FSL_FEATURE_LPSPI_FIFO_SIZEn(0); // The Macro argument is ignored
int chan_tx = -1;
int chan_rx = -1;
@ -302,6 +302,10 @@ STATIC void machine_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8
}
if (!use_dma) {
// Wait until a previous Transfer is finished
while (LPSPI_GetTxFifoCount(self->spi_inst) > 0) {
MICROPY_EVENT_POLL_HOOK
}
// Reconfigure the TCR, required after switch between DMA vs. non-DMA
LPSPI_Enable(self->spi_inst, false); // Disable first before new settings are applied
self->spi_inst->TCR = LPSPI_TCR_CPOL(self->master_config->cpol) | LPSPI_TCR_CPHA(self->master_config->cpha) |