This is a note to let you know that I've just added the patch titled 8250: use callbacks to access UART_DLL/UART_DLM to the 3.14-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: 8250-use-callbacks-to-access-uart_dll-uart_dlm.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 0b41ce991052022c030fd868e03877700220b090 Mon Sep 17 00:00:00 2001 From: Sebastian Frias <sf84@xxxxxxxxxxx> Date: Fri, 18 Dec 2015 17:40:05 +0100 Subject: 8250: use callbacks to access UART_DLL/UART_DLM From: Sebastian Frias <sf84@xxxxxxxxxxx> commit 0b41ce991052022c030fd868e03877700220b090 upstream. Some UART HW has a single register combining UART_DLL/UART_DLM (this was probably forgotten in the change that introduced the callbacks, commit b32b19b8ffc05cbd3bf91c65e205f6a912ca15d9) Fixes: b32b19b8ffc0 ("[SERIAL] 8250: set divisor register correctly ...") Signed-off-by: Sebastian Frias <sf84@xxxxxxxxxxx> Reviewed-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/8250/8250_core.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -686,22 +686,16 @@ static int size_fifo(struct uart_8250_po */ static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p) { - unsigned char old_dll, old_dlm, old_lcr; - unsigned int id; + unsigned char old_lcr; + unsigned int id, old_dl; old_lcr = serial_in(p, UART_LCR); serial_out(p, UART_LCR, UART_LCR_CONF_MODE_A); + old_dl = serial_dl_read(p); + serial_dl_write(p, 0); + id = serial_dl_read(p); + serial_dl_write(p, old_dl); - old_dll = serial_in(p, UART_DLL); - old_dlm = serial_in(p, UART_DLM); - - serial_out(p, UART_DLL, 0); - serial_out(p, UART_DLM, 0); - - id = serial_in(p, UART_DLL) | serial_in(p, UART_DLM) << 8; - - serial_out(p, UART_DLL, old_dll); - serial_out(p, UART_DLM, old_dlm); serial_out(p, UART_LCR, old_lcr); return id; Patches currently in stable-queue which might be from sf84@xxxxxxxxxxx are queue-3.14/8250-use-callbacks-to-access-uart_dll-uart_dlm.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