* [PATCH V2] tty: serial: fsl_lpuart: use the sg count from dma_map_sg
@ 2019-11-07 2:50 Peng Fan
2019-11-07 6:36 ` Peng Fan
2019-11-07 7:02 ` gregkh
0 siblings, 2 replies; 3+ messages in thread
From: Peng Fan @ 2019-11-07 2:50 UTC (permalink / raw)
To: gregkh, jslaby, shawnguo, festevam
Cc: dl-linux-imx, linux-serial, linux-kernel, Andy Duan, Peng Fan, stable
From: Peng Fan <peng.fan@nxp.com>
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>
---
V2:
Assign ret to sport->dma_tx_nents, then we no need to fix dma_unmap_sg
Hi Greg,
I saw v1 patch merged to tty-next, please help to replace with V2 if this
is ok for you, or you need I have a follow up fix for v1.
drivers/tty/serial/fsl_lpuart.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 3e17bb8a0b16..ec5ea098669e 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -436,6 +436,7 @@ static void lpuart_dma_tx(struct lpuart_port *sport)
return;
}
+ sport->dma_tx_nents = ret;
sport->dma_tx_desc = dmaengine_prep_slave_sg(sport->dma_tx_chan, sgl,
sport->dma_tx_nents,
DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
--
2.16.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* RE: [PATCH V2] tty: serial: fsl_lpuart: use the sg count from dma_map_sg
2019-11-07 2:50 [PATCH V2] tty: serial: fsl_lpuart: use the sg count from dma_map_sg Peng Fan
@ 2019-11-07 6:36 ` Peng Fan
2019-11-07 7:02 ` gregkh
1 sibling, 0 replies; 3+ messages in thread
From: Peng Fan @ 2019-11-07 6:36 UTC (permalink / raw)
To: gregkh, jslaby, shawnguo, festevam
Cc: dl-linux-imx, linux-serial, linux-kernel, Andy Duan, stable
> Subject: [PATCH V2] tty: serial: fsl_lpuart: use the sg count from dma_map_sg
Ignore this patch. Keep v1.
Thanks,
Peng.
>
> From: Peng Fan <peng.fan@nxp.com>
>
> 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>
> ---
>
> V2:
> Assign ret to sport->dma_tx_nents, then we no need to fix dma_unmap_sg
> Hi Greg,
> I saw v1 patch merged to tty-next, please help to replace with V2 if this
> is ok for you, or you need I have a follow up fix for v1.
>
> drivers/tty/serial/fsl_lpuart.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index
> 3e17bb8a0b16..ec5ea098669e 100644
> --- a/drivers/tty/serial/fsl_lpuart.c
> +++ b/drivers/tty/serial/fsl_lpuart.c
> @@ -436,6 +436,7 @@ static void lpuart_dma_tx(struct lpuart_port *sport)
> return;
> }
>
> + sport->dma_tx_nents = ret;
> sport->dma_tx_desc = dmaengine_prep_slave_sg(sport->dma_tx_chan,
> sgl,
> sport->dma_tx_nents,
> DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
> --
> 2.16.4
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH V2] tty: serial: fsl_lpuart: use the sg count from dma_map_sg
2019-11-07 2:50 [PATCH V2] tty: serial: fsl_lpuart: use the sg count from dma_map_sg Peng Fan
2019-11-07 6:36 ` Peng Fan
@ 2019-11-07 7:02 ` gregkh
1 sibling, 0 replies; 3+ messages in thread
From: gregkh @ 2019-11-07 7:02 UTC (permalink / raw)
To: Peng Fan
Cc: jslaby, shawnguo, festevam, dl-linux-imx, linux-serial,
linux-kernel, Andy Duan, stable
On Thu, Nov 07, 2019 at 02:50:11AM +0000, Peng Fan wrote:
> From: Peng Fan <peng.fan@nxp.com>
>
> 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>
> ---
>
> V2:
> Assign ret to sport->dma_tx_nents, then we no need to fix dma_unmap_sg
> Hi Greg,
> I saw v1 patch merged to tty-next, please help to replace with V2 if this
> is ok for you, or you need I have a follow up fix for v1.
I can not "replace" anything, my tree does not rebase, sorry. Please
send fix-up patches on top of it if there is any changes that need to
happen.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
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