This is a note to let you know that I've just added the patch titled tty/serial: atmel: fix TX path in atmel_console_write() to the 4.10-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-fix-tx-path-in-atmel_console_write.patch and it can be found in the queue-4.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 497e1e16f45c70574dc9922c7f75c642c2162119 Mon Sep 17 00:00:00 2001 From: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx> Date: Mon, 20 Mar 2017 16:38:57 +0100 Subject: tty/serial: atmel: fix TX path in atmel_console_write() From: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx> commit 497e1e16f45c70574dc9922c7f75c642c2162119 upstream. A side effect of 89d8232411a8 ("tty/serial: atmel_serial: BUG: stop DMA from transmitting in stop_tx") is that the console can be called with TX path disabled. Then the system would hang trying to push charecters out in atmel_console_putchar(). Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx> Fixes: 89d8232411a8 ("tty/serial: atmel_serial: BUG: stop DMA from transmitting in stop_tx") Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/atmel_serial.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -2476,6 +2476,9 @@ static void atmel_console_write(struct c pdc_tx = atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN; atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS); + /* Make sure that tx path is actually able to send characters */ + atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN); + uart_console_write(port, s, count, atmel_console_putchar); /* Patches currently in stable-queue which might be from nicolas.ferre@xxxxxxxxxxxxx are queue-4.10/asoc-atmel-classd-fix-audio-clock-rate.patch queue-4.10/tty-serial-atmel-fix-race-condition-tx-dma.patch queue-4.10/tty-serial-atmel-fix-tx-path-in-atmel_console_write.patch