From 1fe8aa8803536b8030375525a07a152ba8f15363 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 6 Oct 2012 09:04:03 +0100 Subject: [PATCH] SERIAL: omap: don't read back LCR/MCR/EFR There's really no reason to read back these registers while setting the termios modes, provided we keep our cached copies up to date. Remove these readbacks. This has the benefit that we know that the EFR_ECB and MCR_TCRTLR bits will always be clear, so we don't need to keep masking these bits throughout the code. Signed-off-by: Russell King --- drivers/tty/serial/omap-serial.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 4888bd1ab322..6d588e20c648 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -912,8 +912,11 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios, /* Enable AUTORTS and AUTOCTS */ up->efr |= UART_EFR_CTS | UART_EFR_RTS; + /* Ensure MCR RTS is asserted */ + up->mcr |= UART_MCR_RTS; + /* Disable access to TCR/TLR */ - serial_out(up, UART_MCR, up->mcr | UART_MCR_RTS); + serial_out(up, UART_MCR, up->mcr); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_EFR, up->efr); serial_out(up, UART_LCR, cval); @@ -928,10 +931,8 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios, /* Software Flow Control Configuration */ if (up->port.flags & UPF_SOFT_FLOW) { - up->lcr = serial_in(up, UART_LCR); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); - up->efr = serial_in(up, UART_EFR); - serial_out(up, UART_EFR, up->efr & ~UART_EFR_ECB); + serial_out(up, UART_EFR, up->efr); serial_out(up, UART_XON1, termios->c_cc[VSTART]); serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]); @@ -958,8 +959,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios, serial_out(up, UART_EFR, up->efr | UART_EFR_ECB); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); - up->mcr = serial_in(up, UART_MCR); - /* * IXANY Flag: * Enable any character to restart output. @@ -975,7 +974,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios, serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); - serial_out(up, UART_MCR, up->mcr & ~UART_MCR_TCRTLR); + serial_out(up, UART_MCR, up->mcr); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); serial_out(up, UART_EFR, up->efr); serial_out(up, UART_LCR, up->lcr);