diff options
Diffstat (limited to 'src/drivers')
| -rw-r--r-- | src/drivers/spi/spi-generic.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/src/drivers/spi/spi-generic.c b/src/drivers/spi/spi-generic.c index 31a6bc3155..1fcc05d4f3 100644 --- a/src/drivers/spi/spi-generic.c +++ b/src/drivers/spi/spi-generic.c @@ -93,15 +93,24 @@ unsigned int spi_crop_chunk(const struct spi_slave *slave, unsigned int cmd_len, { const struct spi_ctrlr *ctrlr = slave->ctrlr; unsigned int ctrlr_max; + bool deduct_cmd_len; + bool deduct_opcode_len; if (!ctrlr) return 0; + deduct_cmd_len = !!(ctrlr->flags & SPI_CNTRLR_DEDUCT_CMD_LEN); + deduct_opcode_len = !!(ctrlr->flags & SPI_CNTRLR_DEDUCT_OPCODE_LEN); ctrlr_max = ctrlr->max_xfer_size; assert (ctrlr_max != 0); - if (ctrlr->deduct_cmd_len && (ctrlr_max > cmd_len)) + /* Assume opcode is always one byte and deduct it from the cmd_len + as the hardware has a separate register for the opcode. */ + if (deduct_opcode_len) + cmd_len--; + + if (deduct_cmd_len && (ctrlr_max > cmd_len)) ctrlr_max -= cmd_len; return min(ctrlr_max, buf_len); |