This is a note to let you know that I've just added the patch titled tty/serial: at91: maxburst was missing for dma transfers to the 4.0-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-at91-maxburst-was-missing-for-dma-transfers.patch and it can be found in the queue-4.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a8d4e01637902311c5643b69a5c80e2805f04054 Mon Sep 17 00:00:00 2001 From: Ludovic Desroches <ludovic.desroches@xxxxxxxxx> Date: Thu, 16 Apr 2015 16:58:12 +0200 Subject: tty/serial: at91: maxburst was missing for dma transfers From: Ludovic Desroches <ludovic.desroches@xxxxxxxxx> 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@xxxxxxxxx> Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/atmel_serial.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -880,6 +880,7 @@ static int atmel_prepare_tx_dma(struct u 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_slave_config(atmel_port->chan_tx, &config); @@ -1059,6 +1060,7 @@ static int atmel_prepare_rx_dma(struct u 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_slave_config(atmel_port->chan_rx, &config); Patches currently in stable-queue which might be from ludovic.desroches@xxxxxxxxx are queue-4.0/tty-serial-at91-maxburst-was-missing-for-dma-transfers.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html