Messages in this thread | | | Date | Tue, 22 Feb 2022 07:52:36 +0100 | Subject | Re: [PATCH v3 1/9] serial: core: move RS485 configuration tasks from drivers into core | From | Jiri Slaby <> |
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On 22. 02. 22, 7:51, Jiri Slaby wrote: > On 22. 02. 22, 2:14, Lino Sanfilippo wrote: >> Several drivers that support setting the RS485 configuration via >> userspace >> implement one or more of the following tasks: >> >> - in case of an invalid RTS configuration (both RTS after send and RTS on >> send set or both unset) fall back to enable RTS on send and disable >> RTS >> after send >> >> - nullify the padding field of the returned serial_rs485 struct >> >> - copy the configuration into the uart port struct >> >> - limit RTS delays to 100 ms >> >> Move these tasks into the serial core to make them generic and to provide >> a consistent behaviour among all drivers. >> >> Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> >> --- >> drivers/tty/serial/serial_core.c | 29 +++++++++++++++++++++++++++++ >> 1 file changed, 29 insertions(+) >> >> diff --git a/drivers/tty/serial/serial_core.c >> b/drivers/tty/serial/serial_core.c >> index 846192a7b4bf..2b3afe038c1c 100644 >> --- a/drivers/tty/serial/serial_core.c >> +++ b/drivers/tty/serial/serial_core.c >> @@ -42,6 +42,11 @@ static struct lock_class_key port_lock_key; >> #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) >> +/* >> + * Max time with active RTS before/after data is sent. >> + */ >> +#define RS485_MAX_RTS_DELAY 100 /* msecs */ >> + >> static void uart_change_speed(struct tty_struct *tty, struct >> uart_state *state, >> struct ktermios *old_termios); >> static void uart_wait_until_sent(struct tty_struct *tty, int timeout); >> @@ -1282,8 +1287,32 @@ static int uart_set_rs485_config(struct >> uart_port *port, >> if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user))) >> return -EFAULT; >> + /* pick sane settings if the user hasn't */ >> + if (!(rs485.flags & SER_RS485_RTS_ON_SEND) == >> + !(rs485.flags & SER_RS485_RTS_AFTER_SEND)) { >> + pr_warn("invalid RTS setting, using RTS_ON_SEND instead\n"); > > Can't we have a device prefix here, so that everyone knows what device > is affected? Without that, it's not that useful. At least port->name & > port->line could be printed. The uart core uses dev_* prints, but prints > also line as uport->dev can be NULL sometimes.
And this comes from userspace, so should be ratelimited.
-- js suse labs
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