The comment says that we should not allow changes (to bits_per_word/speed_hz) while CS is active, and indeed the code below does fsl_spi_setup_transfer() when the ->cs_change of the previous spi_transfer was set (and for the very first transfer).
So the sanity checking is a bit too strict - we can change it to follow the same logic as is used by the actual transfer loop. Signed-off-by: Rasmus Villemoes <[email protected]> --- drivers/spi/spi-fsl-spi.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c index 6d114daa178a..481b075689b5 100644 --- a/drivers/spi/spi-fsl-spi.c +++ b/drivers/spi/spi-fsl-spi.c @@ -370,13 +370,15 @@ static int fsl_spi_do_one_msg(struct spi_master *master, int status; /* Don't allow changes if CS is active */ - first = list_first_entry(&m->transfers, struct spi_transfer, - transfer_list); + cs_change = 1; list_for_each_entry(t, &m->transfers, transfer_list) { + if (cs_change) + first = t; + cs_change = t->cs_change; if ((first->bits_per_word != t->bits_per_word) || (first->speed_hz != t->speed_hz)) { dev_err(&spi->dev, - "bits_per_word/speed_hz should be same for the same SPI transfer\n"); + "bits_per_word/speed_hz cannot change while CS is active\n"); return -EINVAL; } } -- 2.20.1
