To get the valid data, read DMA status before terminating the DMA. As
dmaengine_terminate_all() deletes the DMA desc.
Fixes: e9ea096dd225 ("serial: tegra: add serial driver")
Signed-off-by: Akhil R <[email protected]>
Signed-off-by: Kartik <[email protected]>
---
drivers/tty/serial/serial-tegra.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index b7170cb9a544..2779b4491f02 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -619,8 +619,8 @@ static void tegra_uart_stop_tx(struct uart_port *u)
if (tup->tx_in_progress != TEGRA_UART_TX_DMA)
return;
- dmaengine_terminate_all(tup->tx_dma_chan);
dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
+ dmaengine_terminate_all(tup->tx_dma_chan);
count = tup->tx_bytes_requested - state.residue;
async_tx_ack(tup->tx_dma_desc);
uart_xmit_advance(&tup->uport, count);
@@ -763,8 +763,8 @@ static void tegra_uart_terminate_rx_dma(struct tegra_uart_port *tup)
return;
}
- dmaengine_terminate_all(tup->rx_dma_chan);
dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
+ dmaengine_terminate_all(tup->rx_dma_chan);
tegra_uart_rx_buffer_push(tup, state.residue);
tup->rx_dma_active = false;
--
2.17.1
To get the valid data, read DMA status before terminating the DMA. As
dmaengine_terminate_all() deletes the DMA desc.
Fixes: e9ea096dd225 ("serial: tegra: add serial driver")
Signed-off-by: Akhil R <[email protected]>
Signed-off-by: Kartik <[email protected]>
---
drivers/tty/serial/serial-tegra.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index b7170cb9a544..2779b4491f02 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -619,8 +619,8 @@ static void tegra_uart_stop_tx(struct uart_port *u)
if (tup->tx_in_progress != TEGRA_UART_TX_DMA)
return;
- dmaengine_terminate_all(tup->tx_dma_chan);
dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
+ dmaengine_terminate_all(tup->tx_dma_chan);
count = tup->tx_bytes_requested - state.residue;
async_tx_ack(tup->tx_dma_desc);
uart_xmit_advance(&tup->uport, count);
@@ -763,8 +763,8 @@ static void tegra_uart_terminate_rx_dma(struct tegra_uart_port *tup)
return;
}
- dmaengine_terminate_all(tup->rx_dma_chan);
dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
+ dmaengine_terminate_all(tup->rx_dma_chan);
tegra_uart_rx_buffer_push(tup, state.residue);
tup->rx_dma_active = false;
--
2.17.1
On Tue, Oct 18, 2022 at 11:55:11AM +0530, Kartik wrote:
> To get the valid data, read DMA status before terminating the DMA. As
> dmaengine_terminate_all() deletes the DMA desc.
>
> Fixes: e9ea096dd225 ("serial: tegra: add serial driver")
>
> Signed-off-by: Akhil R <[email protected]>
> Signed-off-by: Kartik <[email protected]>
> ---
> drivers/tty/serial/serial-tegra.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
Why send this twice?
confused,
greg k-h
On Tue, Oct 18, 2022 at 12:08, Greg KH wrote:
> Why send this twice?
>
> confused,
Hi Greg,
I made a mistake in my "git send-email" and the patch got posted twice.
Regards,
Kartik
On Tue, Oct 18, 2022 at 12:25:16PM +0530, Kartik wrote:
> On Tue, Oct 18, 2022 at 12:08, Greg KH wrote:
> > Why send this twice?
> >
> > confused,
>
> Hi Greg,
>
> I made a mistake in my "git send-email" and the patch got posted twice.
So which one is correct?
On Tue, Oct 18, 2022 at 12:32, Greg KH wrote:
> So which one is correct?
They are basically the same patch. I goofed up while sending it.
Please ignore the previous patch.
Regards,
Kartik
On 18/10/2022 07:25, Kartik wrote:
> To get the valid data, read DMA status before terminating the DMA. As
> dmaengine_terminate_all() deletes the DMA desc.
>
> Fixes: e9ea096dd225 ("serial: tegra: add serial driver")
>
> Signed-off-by: Akhil R <[email protected]>
> Signed-off-by: Kartik <[email protected]>
> ---
> drivers/tty/serial/serial-tegra.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
> index b7170cb9a544..2779b4491f02 100644
> --- a/drivers/tty/serial/serial-tegra.c
> +++ b/drivers/tty/serial/serial-tegra.c
> @@ -619,8 +619,8 @@ static void tegra_uart_stop_tx(struct uart_port *u)
> if (tup->tx_in_progress != TEGRA_UART_TX_DMA)
> return;
>
> - dmaengine_terminate_all(tup->tx_dma_chan);
> dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
> + dmaengine_terminate_all(tup->tx_dma_chan);
The change looks fine to me, but on further review of other similar
drivers I see that they pause first ...
dmaengine_pause(tup->tx_dma_chan);
dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
dmaengine_terminate_all(tup->tx_dma_chan);
This makes sense so that when we calculate the amount of the data
transferred we get the exact amount. Can we add a pause while we are at it?
Thanks!
Jon
--
nvpublic
> The change looks fine to me, but on further review of other similar
> drivers I see that they pause first ...
>
> dmaengine_pause(tup->tx_dma_chan);
> dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
> dmaengine_terminate_all(tup->tx_dma_chan);
>
> This makes sense so that when we calculate the amount of the data
> transferred we get the exact amount. Can we add a pause while we are at it?
>
> Thanks!
> Jon
I agree.. I will include this in v2.
Regards,
Kartik