This is a note to let you know that I've just added the patch titled
tty: serial: fsl_lpuart: use the sg count from dma_map_sg
to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-testing branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will be merged to the tty-next branch sometime soon, after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
From 487ee861de176090b055eba5b252b56a3b9973d6 Mon Sep 17 00:00:00 2001
From: Peng Fan peng.fan@nxp.com Date: Tue, 5 Nov 2019 05:51:10 +0000 Subject: 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 --- drivers/tty/serial/fsl_lpuart.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 22df5f8f48b6..4e128d19e0ad 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -437,8 +437,8 @@ static void lpuart_dma_tx(struct lpuart_port *sport) }
sport->dma_tx_desc = dmaengine_prep_slave_sg(sport->dma_tx_chan, sgl, - sport->dma_tx_nents, - DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT); + ret, DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT); if (!sport->dma_tx_desc) { dma_unmap_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); dev_err(dev, "Cannot prepare TX slave DMA!\n");