| Message ID | 20230624210323.88455-1-julien.malik@unseenlabs.fr |
|---|---|
| State | New |
| Headers | show |
| Series | serial: xilinx_uartps: unset STOPBRK when setting STARTBRK | expand |
Le 24/06/2023 à 23:03, Julien Malik a écrit : > Zynq UG585 states, in chapter B.33, for XUARTPS_CR_STARTBRK: > It can only be set if STPBRK (Stop transmitter break) is not high > > This fixes tcsendbreak, which otherwise does not actually break. > > Signed-Off-By: Julien Malik <julien.malik@unseenlabs.fr> > --- > drivers/tty/serial/xilinx_uartps.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c > index 8e521c69a959..2e69fceaa792 100644 > --- a/drivers/tty/serial/xilinx_uartps.c > +++ b/drivers/tty/serial/xilinx_uartps.c > @@ -657,7 +657,7 @@ static void cdns_uart_break_ctl(struct uart_port *port, int ctl) > status = readl(port->membase + CDNS_UART_CR); > > if (ctl == -1) > - writel(CDNS_UART_CR_STARTBRK | status, > + writel(CDNS_UART_CR_STARTBRK | (~CDNS_UART_CR_STOPBRK & status), > port->membase + CDNS_UART_CR); > else { > if ((status & CDNS_UART_CR_STOPBRK) == 0) Dear reviewers, This is a kind ping to attract more attention to this small patch. The issue and corresponding fix has already been suggested back in 2016 on the xilinx forum [1]. This is my very first patch submission to the kernel. Though I did my best, maybe I did not follow best practices, in which case I'm all ears to suggestions. Best regards, Julien [1] https://support.xilinx.com/s/question/0D52E00006hpUSKSA2/cannot-send-serial-line-break-in-linux-380-trd-145
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 8e521c69a959..2e69fceaa792 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -657,7 +657,7 @@ static void cdns_uart_break_ctl(struct uart_port *port, int ctl) status = readl(port->membase + CDNS_UART_CR); if (ctl == -1) - writel(CDNS_UART_CR_STARTBRK | status, + writel(CDNS_UART_CR_STARTBRK | (~CDNS_UART_CR_STOPBRK & status), port->membase + CDNS_UART_CR); else { if ((status & CDNS_UART_CR_STOPBRK) == 0)
Zynq UG585 states, in chapter B.33, for XUARTPS_CR_STARTBRK: It can only be set if STPBRK (Stop transmitter break) is not high This fixes tcsendbreak, which otherwise does not actually break. Signed-Off-By: Julien Malik <julien.malik@unseenlabs.fr> --- drivers/tty/serial/xilinx_uartps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)