spi: fsl-espi: improve message length handling

Move checking for a zero-length message up in the call chain and
use m->frame_length instead of re-calculating the overall length
of all transfers in the message.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index 2af7463aea8db54772ebe903dfd95ceaf21284da..7b2f997b061fd003fdcc4744ad2bdea33c3d5330 100644 (file)
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -283,8 +283,7 @@ static int fsl_espi_do_trans(struct spi_message *m, struct spi_transfer *trans)
 
        fsl_espi_setup_transfer(spi, trans);
 
-       if (trans->len)
-               ret = fsl_espi_bufs(spi, trans);
+       ret = fsl_espi_bufs(spi, trans);
 
        if (trans->delay_usecs)
                udelay(trans->delay_usecs);
@@ -313,7 +312,7 @@ static int fsl_espi_do_one_msg(struct spi_master *master,
                               struct spi_message *m)
 {
        struct mpc8xxx_spi *mspi = spi_master_get_devdata(m->spi->master);
-       unsigned int delay_usecs = 0, xfer_len = 0;
+       unsigned int delay_usecs = 0;
        struct spi_transfer *t, trans = {};
        int ret;
 
@@ -322,8 +321,6 @@ static int fsl_espi_do_one_msg(struct spi_master *master,
                goto out;
 
        list_for_each_entry(t, &m->transfers, transfer_list) {
-               if ((t->tx_buf) || (t->rx_buf))
-                       xfer_len += t->len;
                if (t->delay_usecs > delay_usecs)
                        delay_usecs = t->delay_usecs;
        }
@@ -331,14 +328,15 @@ static int fsl_espi_do_one_msg(struct spi_master *master,
        t = list_first_entry(&m->transfers, struct spi_transfer,
                             transfer_list);
 
-       trans.len = xfer_len;
+       trans.len = m->frame_length;
        trans.speed_hz = t->speed_hz;
        trans.bits_per_word = t->bits_per_word;
        trans.delay_usecs = delay_usecs;
        trans.tx_buf = mspi->local_buf;
        trans.rx_buf = mspi->local_buf;
 
-       ret = fsl_espi_trans(m, &trans);
+       if (trans.len)
+               ret = fsl_espi_trans(m, &trans);
 
        m->actual_length = ret ? 0 : trans.len;
 out: