diff options
| author | Michal Suchanek <hramrach@gmail.com> | 2016-06-13 17:46:49 +0000 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2016-06-14 10:05:08 +0100 |
| commit | 6d9fe44bd73d567d04d3a68a2d2fa521ab9532f2 (patch) | |
| tree | 862f44d73573de039a5b35a2fce7f0a154530a43 | |
| parent | 1a695a905c18548062509178b98bc91e67510864 (diff) | |
| download | linux-6d9fe44bd73d567d04d3a68a2d2fa521ab9532f2.tar.bz2 | |
spi: sun4i: fix FIFO limit
When testing SPI without DMA I noticed that filling the FIFO on the
spi controller causes timeout.
Always leave room for one byte in the FIFO.
Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
| -rw-r--r-- | drivers/spi/spi-sun4i.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c index 1ddd9e2309b6..e7e4aecb3295 100644 --- a/drivers/spi/spi-sun4i.c +++ b/drivers/spi/spi-sun4i.c @@ -179,7 +179,10 @@ static int sun4i_spi_transfer_one(struct spi_master *master, /* We don't support transfer larger than the FIFO */ if (tfr->len > SUN4I_FIFO_DEPTH) - return -EINVAL; + return -EMSGSIZE; + + if (tfr->tx_buf && tfr->len >= SUN4I_FIFO_DEPTH) + return -EMSGSIZE; reinit_completion(&sspi->done); sspi->tx_buf = tfr->tx_buf; @@ -269,8 +272,12 @@ static int sun4i_spi_transfer_one(struct spi_master *master, sun4i_spi_write(sspi, SUN4I_BURST_CNT_REG, SUN4I_BURST_CNT(tfr->len)); sun4i_spi_write(sspi, SUN4I_XMIT_CNT_REG, SUN4I_XMIT_CNT(tx_len)); - /* Fill the TX FIFO */ - sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH); + /* + * Fill the TX FIFO + * Filling the FIFO fully causes timeout for some reason + * at least on spi2 on A10s + */ + sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH - 1); /* Enable the interrupts */ sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, SUN4I_INT_CTL_TC); |