diff options
| author | Serge Semin <Sergey.Semin@baikalelectronics.ru> | 2020-09-20 14:23:15 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-09-29 16:37:08 +0100 |
| commit | be3034d9f9f3ea28588932d10bba6d06b71489a7 (patch) | |
| tree | c9b95d9fdb2280ac65baf0be3bc38741f147b060 /drivers/spi | |
| parent | a874d811f0c2d285fd7409b5fc569c454c05c835 (diff) | |
spi: dw-dma: Check rx_buf availability in the xfer method
Checking rx_buf for being NULL and returning NULL from the Rx-channel
preparation method doesn't let us to distinguish that situation from
errors happening during the Rx SG-list preparation. So it's better to make
sure that the rx_buf not-NULL and full-duplex communication is requested
prior calling the Rx preparation method.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112322.24585-5-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-dw-dma.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/drivers/spi/spi-dw-dma.c b/drivers/spi/spi-dw-dma.c index da17897b8acb..d2a67dee1a66 100644 --- a/drivers/spi/spi-dw-dma.c +++ b/drivers/spi/spi-dw-dma.c @@ -369,9 +369,6 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws, { struct dma_async_tx_descriptor *rxdesc; - if (!xfer->rx_buf) - return NULL; - rxdesc = dmaengine_prep_slave_sg(dws->rxchan, xfer->rx_sg.sgl, xfer->rx_sg.nents, @@ -435,10 +432,12 @@ static int dw_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer) return -EINVAL; /* Prepare the RX dma transfer */ - rxdesc = dw_spi_dma_prepare_rx(dws, xfer); + if (xfer->rx_buf) { + rxdesc = dw_spi_dma_prepare_rx(dws, xfer); + if (!rxdesc) + return -EINVAL; - /* rx must be started before tx due to spi instinct */ - if (rxdesc) { + /* rx must be started before tx due to spi instinct */ set_bit(RX_BUSY, &dws->dma_chan_busy); dmaengine_submit(rxdesc); dma_async_issue_pending(dws->rxchan); @@ -458,7 +457,7 @@ static int dw_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer) return ret; } - if (rxdesc && dws->master->cur_msg->status == -EINPROGRESS) + if (xfer->rx_buf && dws->master->cur_msg->status == -EINPROGRESS) ret = dw_spi_dma_wait_rx_done(dws); return ret; |