| Message ID | 20220222011433.8761-2-LinoSanfilippo@gmx.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3,1/9] serial: core: move RS485 configuration tasks from drivers into core | expand |
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. Hm, we could introduce uart_print family (to print something like what is in uart_report_port). thanks,
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.
Hi, > 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. > Right, ratelimiting makes sense here. I will change it as suggested in the next patch version. Thanks a lot for the review. Regards, Lino
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"); + rs485.flags |= SER_RS485_RTS_ON_SEND; + rs485.flags &= ~SER_RS485_RTS_AFTER_SEND; + } + + if (rs485.delay_rts_before_send > RS485_MAX_RTS_DELAY) { + rs485.delay_rts_before_send = RS485_MAX_RTS_DELAY; + pr_warn("RTS delay before sending clamped to %u ms\n", + rs485.delay_rts_before_send); + } + + if (rs485.delay_rts_after_send > RS485_MAX_RTS_DELAY) { + rs485.delay_rts_after_send = RS485_MAX_RTS_DELAY; + pr_warn("RTS delay after sending clamped to %u ms\n", + rs485.delay_rts_after_send); + } + /* Return clean padding area to userspace */ + memset(rs485.padding, 0, sizeof(rs485.padding)); + spin_lock_irqsave(&port->lock, flags); ret = port->rs485_config(port, &rs485); + if (!ret) + port->rs485 = rs485; spin_unlock_irqrestore(&port->lock, flags); if (ret) return ret;
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(+) base-commit: a603ca60cebff8589882427a67f870ed946b3fc8