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| author | Nicolas Saenz Julienne <nsaenzjulienne@suse.de> | 2019-05-09 16:39:59 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2019-05-13 13:14:38 +0100 |
| commit | 3393f7d924510cfdb2ff9594eac2590d5de16d92 (patch) | |
| tree | 2849b71687370336dae119a67f0bed6f43ece2fe /drivers/spi/spi-bcm2835.c | |
| parent | 35ceb6759d1b6a0e085fa46d44867d3bc6fb4d59 (diff) | |
| download | lwn-3393f7d924510cfdb2ff9594eac2590d5de16d92.tar.gz lwn-3393f7d924510cfdb2ff9594eac2590d5de16d92.zip | |
spi: bcm2835: only split transfers that exceed DLEN if DMA available
There is no use for this when performing non DMA operations. So we
bypass the split.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-bcm2835.c')
| -rw-r--r-- | drivers/spi/spi-bcm2835.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 3a9b2187787a..f87a023a445a 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -895,15 +895,17 @@ static int bcm2835_spi_prepare_message(struct spi_master *master, u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS); int ret; - /* - * DMA transfers are limited to 16 bit (0 to 65535 bytes) by the SPI HW - * due to DLEN. Split up transfers (32-bit FIFO aligned) if the limit is - * exceeded. - */ - ret = spi_split_transfers_maxsize(master, msg, 65532, - GFP_KERNEL | GFP_DMA); - if (ret) - return ret; + if (master->can_dma) { + /* + * DMA transfers are limited to 16 bit (0 to 65535 bytes) by + * the SPI HW due to DLEN. Split up transfers (32-bit FIFO + * aligned) if the limit is exceeded. + */ + ret = spi_split_transfers_maxsize(master, msg, 65532, + GFP_KERNEL | GFP_DMA); + if (ret) + return ret; + } cs &= ~(BCM2835_SPI_CS_CPOL | BCM2835_SPI_CS_CPHA); |