This is a note to let you know that I've just added the patch titled
tty: serial: atmel: Call dma_async_issue_pending()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tty-serial-atmel-call-dma_async_issue_pending.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 548e4475862472723ed980acd25331c4de21552f
Author: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
Date: Thu Nov 25 11:00:18 2021 +0200
tty: serial: atmel: Call dma_async_issue_pending()
[ Upstream commit 4f4b9b5895614eb2e2b5f4cab7858f44bd113e1b ]
The driver wrongly assummed that tx_submit() will start the transfer,
which is not the case, now that the at_xdmac driver is fixed. tx_submit
is supposed to push the current transaction descriptor to a pending queue,
waiting for issue_pending to be called. issue_pending must start the
transfer, not tx_submit.
Fixes: 34df42f59a60 ("serial: at91: add rx dma support")
Fixes: 08f738be88bb ("serial: at91: add tx dma support")
Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20211125090028.786832-4-tudor.ambarus@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 396fe8c51f93b..602065bfc9bb8 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1009,6 +1009,8 @@ static void atmel_tx_dma(struct uart_port *port)
atmel_port->cookie_tx);
return;
}
+
+ dma_async_issue_pending(chan);
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
@@ -1275,6 +1277,8 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
goto chan_err;
}
+ dma_async_issue_pending(atmel_port->chan_rx);
+
return 0;
chan_err:
