diff options
| -rw-r--r-- | drivers/spi/spi-fsl-spi.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c index e2b341943796..b36ac6aa3b1f 100644 --- a/drivers/spi/spi-fsl-spi.c +++ b/drivers/spi/spi-fsl-spi.c @@ -363,12 +363,28 @@ static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t, static int fsl_spi_do_one_msg(struct spi_master *master, struct spi_message *m) { + struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master); struct spi_device *spi = m->spi; struct spi_transfer *t, *first; unsigned int cs_change; const int nsecs = 50; int status, last_bpw; + /* + * In CPU mode, optimize large byte transfers to use larger + * bits_per_word values to reduce number of interrupts taken. + */ + if (!(mpc8xxx_spi->flags & SPI_CPM_MODE)) { + list_for_each_entry(t, &m->transfers, transfer_list) { + if (t->len < 256 || t->bits_per_word != 8) + continue; + if ((t->len & 3) == 0) + t->bits_per_word = 32; + else if ((t->len & 1) == 0) + t->bits_per_word = 16; + } + } + /* Don't allow changes if CS is active */ cs_change = 1; list_for_each_entry(t, &m->transfers, transfer_list) { |