On Tue, Jan 17, 2012 at 03:59:49PM +0530, Shreshtha Kumar SAHU wrote:
> From: Shreshtha Kumar Sahu <shreshthakumar.sahu@xxxxxxxxxxxxxx>
>
> In present driver, shutdown clears RTS in CR register. But the
> documentation "Documentation/serial/driver" suggests not to
> disable RTS in shutdown(). Also RTS is preserved between shutdown
> and startup calls, i.e. it is restored in startup if it was enabled
> during shutdown. So that if autorts is set and RTS is set using
> pl011_set_mctrl then it should continue even after shutdown->startup
> sequence. And hence during set_termios it will enable RTS only if RTS
> bit is set in UARTx_CR register. For throttling/unthrottling user
> should call pl011_set_mctrl.
>
> Change-Id: I743f33fb10e7e655657cd5dae1ec585e914a65bc
Please get rid of this line.
> Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@xxxxxxxxxxxxxx>
> Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> drivers/tty/serial/amba-pl011.c | 17 ++++++++++++++++-
> 1 files changed, 16 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index 6958594..46a4690 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -160,6 +160,7 @@ struct uart_amba_port {
> unsigned int lcrh_tx; /* vendor-specific */
> unsigned int lcrh_rx; /* vendor-specific */
> bool autorts;
> + bool rts_state; /* state during shutdown */
Do we really need a variable to track this?
> char type[12];
> bool interrupt_may_hang; /* vendor-specific */
> #ifdef CONFIG_DMA_ENGINE
> @@ -1412,6 +1413,8 @@ static int pl011_startup(struct uart_port *port)
> barrier();
>
> cr = UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE;
> + if (uap->rts_state)
> + cr |= UART011_CR_RTS;
> writew(cr, uap->port.membase + UART011_CR);
Note that this should preserve DTR as well.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of:
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