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| author | Sebastian Frias <sf84@laposte.net> | 2015-12-18 17:40:05 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-04-12 09:12:44 -0700 |
| commit | ef431b61064d6e7252314ddbfb8dd8d3413d5e9c (patch) | |
| tree | 04f29dbff579a2958c50c0fca19f772672b34502 | |
| parent | 8aabc4b9c62baf2945c82277048044349f27b99f (diff) | |
| download | lwn-ef431b61064d6e7252314ddbfb8dd8d3413d5e9c.tar.gz lwn-ef431b61064d6e7252314ddbfb8dd8d3413d5e9c.zip | |
8250: use callbacks to access UART_DLL/UART_DLM
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@laposte.net>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/8250/8250_core.c | 18 |
1 files changed, 6 insertions, 12 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 612dfc720738..9fffc7295af1 100644 --- 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_port *up) */ 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; |