tree 4814f2d7f16e9fc675781b145eaf187a45660f91
parent 879516870d7a8e7ec017efa9be49d86dd4e04d3b
author Peng Fan <peng.fan@nxp.com> 1572933070 +0000
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1572974281 +0100

tty: serial: fsl_lpuart: use the sg count from dma_map_sg

The dmaengine_prep_slave_sg needs to use sg count returned
by dma_map_sg, not use sport->dma_tx_nents, because the return
value of dma_map_sg is not always same with "nents".

When enabling iommu for lpuart + edma, iommu framework may concatenate
two sgs into one.

Fixes: 6250cc30c4c4e ("tty: serial: fsl_lpuart: Use scatter/gather DMA for Tx")
Cc: <stable@vger.kernel.org>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1572932977-17866-1-git-send-email-peng.fan@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>