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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>
This commit is contained in:
Nicolas Saenz Julienne 2019-05-09 16:39:59 +02:00 committed by Mark Brown
parent 35ceb6759d
commit 3393f7d924
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GPG Key ID: 24D68B725D5487D0
1 changed files with 11 additions and 9 deletions
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20
drivers/spi/spi-bcm2835.c
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@ -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);