diff options
| author | Michal Suchanek <hramrach@gmail.com> | 2016-06-13 20:46:49 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-10 12:49:28 +0300 |
| commit | 9162d29bc48a43a30217fc1fd939023a75ce604b (patch) | |
| tree | 10b09a302df594bd9c0234f4bcea05bb6b725a22 /drivers/spi | |
| parent | 873b6e316a581c976a29a1d8c889c76394d7393d (diff) | |
| download | linux-9162d29bc48a43a30217fc1fd939023a75ce604b.tar.xz | |
spi: sun4i: fix FIFO limit
commit 6d9fe44bd73d567d04d3a68a2d2fa521ab9532f2 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/spi')
| -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 836328730457..39d7c7c70112 100644 --- a/drivers/spi/spi-sun4i.c +++ b/drivers/spi/spi-sun4i.c @@ -177,7 +177,10 @@ 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; @@ -270,8 +273,12 @@ 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); |