| Message ID | 20170915140411.31716-10-romain.izard.pro@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Various patches for SAMA5D2 backup mode | expand |
On 15/09/2017 at 16:04, Romain Izard wrote: > The atmel serial port driver reported the following warning on suspend: > atmel_usart f8020000.serial: ttyS1: Unable to drain transmitter > > As the ATMEL_US_TXEMPTY status bit in ATMEL_US_CSR is always cleared > when the transmitter is disabled, we need to know the transmitter's > state to return the real fifo state. And as ATMEL_US_CR is write-only, > it is necessary to save the state of the transmitter in a local > variable, and update the variable when TXEN and TXDIS is written in > ATMEL_US_CR. > > After those changes, atmel_tx_empty can return "empty" on suspend, the > warning in uart_suspend_port disappears, and suspending is 20ms shorter > for each enabled Atmel serial port. > > Signed-off-by: Romain Izard <romain.izard.pro@gmail.com> Tested-by: Nicolas Ferre <nicolas.ferre@microchip.com> on sama5d2 Xplained. Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> > --- > drivers/tty/serial/atmel_serial.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c > index 7551cab438ff..783af6648be0 100644 > --- a/drivers/tty/serial/atmel_serial.c > +++ b/drivers/tty/serial/atmel_serial.c > @@ -171,6 +171,7 @@ struct atmel_uart_port { > bool has_hw_timer; > struct timer_list uart_timer; > > + bool tx_stopped; > bool suspended; > unsigned int pending; > unsigned int pending_status; > @@ -380,6 +381,10 @@ static int atmel_config_rs485(struct uart_port *port, > */ > static u_int atmel_tx_empty(struct uart_port *port) > { > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > + > + if (atmel_port->tx_stopped) > + return TIOCSER_TEMT; > return (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXEMPTY) ? > TIOCSER_TEMT : > 0; > @@ -485,6 +490,7 @@ static void atmel_stop_tx(struct uart_port *port) > * is fully transmitted. > */ > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS); > + atmel_port->tx_stopped = true; > > /* Disable interrupts */ > atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); > @@ -492,6 +498,7 @@ static void atmel_stop_tx(struct uart_port *port) > if ((port->rs485.flags & SER_RS485_ENABLED) && > !(port->rs485.flags & SER_RS485_RX_DURING_TX)) > atmel_start_rx(port); > + > } > > /* > @@ -521,6 +528,7 @@ static void atmel_start_tx(struct uart_port *port) > > /* re-enable the transmitter */ > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN); > + atmel_port->tx_stopped = false; > } > > /* > @@ -1866,6 +1874,7 @@ static int atmel_startup(struct uart_port *port) > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); > /* enable xmit & rcvr */ > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); > + atmel_port->tx_stopped = false; > > setup_timer(&atmel_port->uart_timer, > atmel_uart_timer_callback, > @@ -2122,6 +2131,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > > /* disable receiver and transmitter */ > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXDIS); > + atmel_port->tx_stopped = true; > > /* mode */ > if (port->rs485.flags & SER_RS485_ENABLED) { > @@ -2207,6 +2217,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > atmel_uart_writel(port, ATMEL_US_BRGR, quot); > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); > + atmel_port->tx_stopped = false; > > /* restore interrupts */ > atmel_uart_writel(port, ATMEL_US_IER, imr); > @@ -2450,6 +2461,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) > > /* Make sure that tx path is actually able to send characters */ > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN); > + atmel_port->tx_stopped = false; > > uart_console_write(port, s, count, atmel_console_putchar); > > @@ -2511,6 +2523,7 @@ static int __init atmel_console_setup(struct console *co, char *options) > { > int ret; > struct uart_port *port = &atmel_ports[co->index].uart; > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > int baud = 115200; > int bits = 8; > int parity = 'n'; > @@ -2528,6 +2541,7 @@ static int __init atmel_console_setup(struct console *co, char *options) > atmel_uart_writel(port, ATMEL_US_IDR, -1); > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); > + atmel_port->tx_stopped = false; > > if (options) > uart_parse_options(options, &baud, &parity, &bits, &flow); >
On 15/09/2017 16:04, Romain Izard wrote: > The atmel serial port driver reported the following warning on suspend: > atmel_usart f8020000.serial: ttyS1: Unable to drain transmitter > > As the ATMEL_US_TXEMPTY status bit in ATMEL_US_CSR is always cleared > when the transmitter is disabled, we need to know the transmitter's > state to return the real fifo state. And as ATMEL_US_CR is write-only, > it is necessary to save the state of the transmitter in a local > variable, and update the variable when TXEN and TXDIS is written in > ATMEL_US_CR. > > After those changes, atmel_tx_empty can return "empty" on suspend, the > warning in uart_suspend_port disappears, and suspending is 20ms shorter > for each enabled Atmel serial port. > > Signed-off-by: Romain Izard <romain.izard.pro@gmail.com> > --- > drivers/tty/serial/atmel_serial.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c > index 7551cab438ff..783af6648be0 100644 > --- a/drivers/tty/serial/atmel_serial.c > +++ b/drivers/tty/serial/atmel_serial.c > @@ -171,6 +171,7 @@ struct atmel_uart_port { > bool has_hw_timer; > struct timer_list uart_timer; > > + bool tx_stopped; > bool suspended; > unsigned int pending; > unsigned int pending_status; > @@ -380,6 +381,10 @@ static int atmel_config_rs485(struct uart_port *port, > */ > static u_int atmel_tx_empty(struct uart_port *port) > { > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > + > + if (atmel_port->tx_stopped) > + return TIOCSER_TEMT; > return (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXEMPTY) ? > TIOCSER_TEMT : > 0; > @@ -485,6 +490,7 @@ static void atmel_stop_tx(struct uart_port *port) > * is fully transmitted. > */ > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS); > + atmel_port->tx_stopped = true; > > /* Disable interrupts */ > atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); > @@ -492,6 +498,7 @@ static void atmel_stop_tx(struct uart_port *port) > if ((port->rs485.flags & SER_RS485_ENABLED) && > !(port->rs485.flags & SER_RS485_RX_DURING_TX)) > atmel_start_rx(port); > + > } This line feed is not needed. Otherwise, Acked-by: Richard Genoud <richard.genoud@gmail.com> > > /* > @@ -521,6 +528,7 @@ static void atmel_start_tx(struct uart_port *port) > > /* re-enable the transmitter */ > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN); > + atmel_port->tx_stopped = false; > } > > /* > @@ -1866,6 +1874,7 @@ static int atmel_startup(struct uart_port *port) > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); > /* enable xmit & rcvr */ > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); > + atmel_port->tx_stopped = false; > > setup_timer(&atmel_port->uart_timer, > atmel_uart_timer_callback, > @@ -2122,6 +2131,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > > /* disable receiver and transmitter */ > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXDIS); > + atmel_port->tx_stopped = true; > > /* mode */ > if (port->rs485.flags & SER_RS485_ENABLED) { > @@ -2207,6 +2217,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > atmel_uart_writel(port, ATMEL_US_BRGR, quot); > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); > + atmel_port->tx_stopped = false; > > /* restore interrupts */ > atmel_uart_writel(port, ATMEL_US_IER, imr); > @@ -2450,6 +2461,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) > > /* Make sure that tx path is actually able to send characters */ > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN); > + atmel_port->tx_stopped = false; > > uart_console_write(port, s, count, atmel_console_putchar); > > @@ -2511,6 +2523,7 @@ static int __init atmel_console_setup(struct console *co, char *options) > { > int ret; > struct uart_port *port = &atmel_ports[co->index].uart; > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > int baud = 115200; > int bits = 8; > int parity = 'n'; > @@ -2528,6 +2541,7 @@ static int __init atmel_console_setup(struct console *co, char *options) > atmel_uart_writel(port, ATMEL_US_IDR, -1); > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); > atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); > + atmel_port->tx_stopped = false; > > if (options) > uart_parse_options(options, &baud, &parity, &bits, &flow); > -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 7551cab438ff..783af6648be0 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -171,6 +171,7 @@ struct atmel_uart_port { bool has_hw_timer; struct timer_list uart_timer; + bool tx_stopped; bool suspended; unsigned int pending; unsigned int pending_status; @@ -380,6 +381,10 @@ static int atmel_config_rs485(struct uart_port *port, */ static u_int atmel_tx_empty(struct uart_port *port) { + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + + if (atmel_port->tx_stopped) + return TIOCSER_TEMT; return (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0; @@ -485,6 +490,7 @@ static void atmel_stop_tx(struct uart_port *port) * is fully transmitted. */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS); + atmel_port->tx_stopped = true; /* Disable interrupts */ atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); @@ -492,6 +498,7 @@ static void atmel_stop_tx(struct uart_port *port) if ((port->rs485.flags & SER_RS485_ENABLED) && !(port->rs485.flags & SER_RS485_RX_DURING_TX)) atmel_start_rx(port); + } /* @@ -521,6 +528,7 @@ static void atmel_start_tx(struct uart_port *port) /* re-enable the transmitter */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN); + atmel_port->tx_stopped = false; } /* @@ -1866,6 +1874,7 @@ static int atmel_startup(struct uart_port *port) atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); /* enable xmit & rcvr */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); + atmel_port->tx_stopped = false; setup_timer(&atmel_port->uart_timer, atmel_uart_timer_callback, @@ -2122,6 +2131,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, /* disable receiver and transmitter */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXDIS); + atmel_port->tx_stopped = true; /* mode */ if (port->rs485.flags & SER_RS485_ENABLED) { @@ -2207,6 +2217,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, atmel_uart_writel(port, ATMEL_US_BRGR, quot); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); + atmel_port->tx_stopped = false; /* restore interrupts */ atmel_uart_writel(port, ATMEL_US_IER, imr); @@ -2450,6 +2461,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) /* Make sure that tx path is actually able to send characters */ atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN); + atmel_port->tx_stopped = false; uart_console_write(port, s, count, atmel_console_putchar); @@ -2511,6 +2523,7 @@ static int __init atmel_console_setup(struct console *co, char *options) { int ret; struct uart_port *port = &atmel_ports[co->index].uart; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); int baud = 115200; int bits = 8; int parity = 'n'; @@ -2528,6 +2541,7 @@ static int __init atmel_console_setup(struct console *co, char *options) atmel_uart_writel(port, ATMEL_US_IDR, -1); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); + atmel_port->tx_stopped = false; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow);
The atmel serial port driver reported the following warning on suspend: atmel_usart f8020000.serial: ttyS1: Unable to drain transmitter As the ATMEL_US_TXEMPTY status bit in ATMEL_US_CSR is always cleared when the transmitter is disabled, we need to know the transmitter's state to return the real fifo state. And as ATMEL_US_CR is write-only, it is necessary to save the state of the transmitter in a local variable, and update the variable when TXEN and TXDIS is written in ATMEL_US_CR. After those changes, atmel_tx_empty can return "empty" on suspend, the warning in uart_suspend_port disappears, and suspending is 20ms shorter for each enabled Atmel serial port. Signed-off-by: Romain Izard <romain.izard.pro@gmail.com> --- drivers/tty/serial/atmel_serial.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)