[3.13.y-ckt stable] Patch "tty/serial: at91: maxburst was missing for dma transfers" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    tty/serial: at91: maxburst was missing for dma transfers

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt22.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From f46e418850928afbc309e80928267685391d981c Mon Sep 17 00:00:00 2001
From: Ludovic Desroches <ludovic.desroches at atmel.com>
Date: Thu, 16 Apr 2015 16:58:12 +0200
Subject: tty/serial: at91: maxburst was missing for dma transfers

commit a8d4e01637902311c5643b69a5c80e2805f04054 upstream.

Maxburst was not set when doing the dma slave configuration. This value
is checked by the recently introduced xdmac. It causes an error when
doing the slave configuration and so prevents from using dma.

Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre at atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/tty/serial/atmel_serial.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 52ada70..cbd1bdf 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -757,6 +757,7 @@ static int atmel_prepare_tx_dma(struct uart_port *port)
 	config.direction = DMA_MEM_TO_DEV;
 	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 	config.dst_addr = port->mapbase + ATMEL_US_THR;
+	config.dst_maxburst = 1;

 	ret = dmaengine_device_control(atmel_port->chan_tx,
 					DMA_SLAVE_CONFIG,
@@ -921,6 +922,7 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
 	config.direction = DMA_DEV_TO_MEM;
 	config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 	config.src_addr = port->mapbase + ATMEL_US_RHR;
+	config.src_maxburst = 1;

 	ret = dmaengine_device_control(atmel_port->chan_rx,
 					DMA_SLAVE_CONFIG,
--
1.9.1