[{"id":1770828,"web_url":"http://patchwork.ozlabs.org/comment/1770828/","msgid":"<380a15d6-c180-316f-a56b-011acd02df59@microchip.com>","list_archive_url":null,"date":"2017-09-19T10:19:33","subject":"Re: [PATCH v2 9/9] tty/serial: atmel: Prevent a warning on suspend","submitter":{"id":71036,"url":"http://patchwork.ozlabs.org/api/people/71036/","name":"Nicolas Ferre","email":"nicolas.ferre@microchip.com"},"content":"On 15/09/2017 at 16:04, Romain Izard wrote:\n> The atmel serial port driver reported the following warning on suspend:\n> atmel_usart f8020000.serial: ttyS1: Unable to drain transmitter\n> \n> As the ATMEL_US_TXEMPTY status bit in ATMEL_US_CSR is always cleared\n> when the transmitter is disabled, we need to know the transmitter's\n> state to return the real fifo state. And as ATMEL_US_CR is write-only,\n> it is necessary to save the state of the transmitter in a local\n> variable, and update the variable when TXEN and TXDIS is written in\n> ATMEL_US_CR.\n> \n> After those changes, atmel_tx_empty can return \"empty\" on suspend, the\n> warning in uart_suspend_port disappears, and suspending is 20ms shorter\n> for each enabled Atmel serial port.\n> \n> Signed-off-by: Romain Izard \n\nTested-by: Nicolas Ferre \non sama5d2 Xplained.\n\nAcked-by: Nicolas Ferre \n\n> ---\n> drivers/tty/serial/atmel_serial.c | 14 ++++++++++++++\n> 1 file changed, 14 insertions(+)\n> \n> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c\n> index 7551cab438ff..783af6648be0 100644\n> --- a/drivers/tty/serial/atmel_serial.c\n> +++ b/drivers/tty/serial/atmel_serial.c\n> @@ -171,6 +171,7 @@ struct atmel_uart_port {\n> \tbool\t\t\thas_hw_timer;\n> \tstruct timer_list\tuart_timer;\n> \n> +\tbool\t\t\ttx_stopped;\n> \tbool\t\t\tsuspended;\n> \tunsigned int\t\tpending;\n> \tunsigned int\t\tpending_status;\n> @@ -380,6 +381,10 @@ static int atmel_config_rs485(struct uart_port *port,\n> */\n> static u_int atmel_tx_empty(struct uart_port *port)\n> {\n> +\tstruct atmel_uart_port *atmel_port = to_atmel_uart_port(port);\n> +\n> +\tif (atmel_port->tx_stopped)\n> +\t\treturn TIOCSER_TEMT;\n> \treturn (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXEMPTY) ?\n> \t\tTIOCSER_TEMT :\n> \t\t0;\n> @@ -485,6 +490,7 @@ static void atmel_stop_tx(struct uart_port *port)\n> \t * is fully transmitted.\n> \t */\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS);\n> +\tatmel_port->tx_stopped = true;\n> \n> \t/* Disable interrupts */\n> \tatmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);\n> @@ -492,6 +498,7 @@ static void atmel_stop_tx(struct uart_port *port)\n> \tif ((port->rs485.flags & SER_RS485_ENABLED) &&\n> \t !(port->rs485.flags & SER_RS485_RX_DURING_TX))\n> \t\tatmel_start_rx(port);\n> +\n> }\n> \n> /*\n> @@ -521,6 +528,7 @@ static void atmel_start_tx(struct uart_port *port)\n> \n> \t/* re-enable the transmitter */\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN);\n> +\tatmel_port->tx_stopped = false;\n> }\n> \n> /*\n> @@ -1866,6 +1874,7 @@ static int atmel_startup(struct uart_port *port)\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);\n> \t/* enable xmit & rcvr */\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);\n> +\tatmel_port->tx_stopped = false;\n> \n> \tsetup_timer(&atmel_port->uart_timer,\n> \t\t\tatmel_uart_timer_callback,\n> @@ -2122,6 +2131,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,\n> \n> \t/* disable receiver and transmitter */\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXDIS);\n> +\tatmel_port->tx_stopped = true;\n> \n> \t/* mode */\n> \tif (port->rs485.flags & SER_RS485_ENABLED) {\n> @@ -2207,6 +2217,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,\n> \tatmel_uart_writel(port, ATMEL_US_BRGR, quot);\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);\n> +\tatmel_port->tx_stopped = false;\n> \n> \t/* restore interrupts */\n> \tatmel_uart_writel(port, ATMEL_US_IER, imr);\n> @@ -2450,6 +2461,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count)\n> \n> \t/* Make sure that tx path is actually able to send characters */\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN);\n> +\tatmel_port->tx_stopped = false;\n> \n> \tuart_console_write(port, s, count, atmel_console_putchar);\n> \n> @@ -2511,6 +2523,7 @@ static int __init atmel_console_setup(struct console *co, char *options)\n> {\n> \tint ret;\n> \tstruct uart_port *port = &atmel_ports[co->index].uart;\n> +\tstruct atmel_uart_port *atmel_port = to_atmel_uart_port(port);\n> \tint baud = 115200;\n> \tint bits = 8;\n> \tint parity = 'n';\n> @@ -2528,6 +2541,7 @@ static int __init atmel_console_setup(struct console *co, char *options)\n> \tatmel_uart_writel(port, ATMEL_US_IDR, -1);\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);\n> +\tatmel_port->tx_stopped = false;\n> \n> \tif (options)\n> \t\tuart_parse_options(options, &baud, &parity, &bits, &flow);\n>","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":"ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; 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d=\"scan'208\";a=\"7163947\"","Subject":"Re: [PATCH v2 9/9] tty/serial: atmel: Prevent a warning on suspend","To":"Romain Izard ,\n\tAlexandre Belloni ,\n\tBoris Brezillon ,\n\tMichael Turquette ,\n\tStephen Boyd ,\n\tLudovic Desroches ,\n\tWenyou Yang , Josh Wu ,\n\tDavid Woodhouse ,\n\tBrian Norris ,\n\tMarek Vasut ,\n\tCyrille Pitchen ,\n\tThierry Reding ,\n\tRichard Genoud ,\n\tGreg Kroah-Hartman ,\n\tAlan Stern ","CC":", ,\n\t, ,\n\t, ,\n\t","References":"<20170915140411.31716-1-romain.izard.pro@gmail.com>\n\t<20170915140411.31716-10-romain.izard.pro@gmail.com>","From":"Nicolas Ferre ","Organization":"microchip","Message-ID":"<380a15d6-c180-316f-a56b-011acd02df59@microchip.com>","Date":"Tue, 19 Sep 2017 12:19:33 +0200","User-Agent":"Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101\n\tThunderbird/52.3.0","MIME-Version":"1.0","In-Reply-To":"<20170915140411.31716-10-romain.izard.pro@gmail.com>","Content-Type":"text/plain; charset=\"utf-8\"","Content-Language":"en-US","Content-Transfer-Encoding":"7bit","Sender":"linux-pwm-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"linux-pwm@vger.kernel.org"}},{"id":1771924,"web_url":"http://patchwork.ozlabs.org/comment/1771924/","msgid":"","list_archive_url":null,"date":"2017-09-20T14:35:05","subject":"Re: [PATCH v2 9/9] tty/serial: atmel: Prevent a warning on suspend","submitter":{"id":810,"url":"http://patchwork.ozlabs.org/api/people/810/","name":"Richard Genoud","email":"richard.genoud@gmail.com"},"content":"On 15/09/2017 16:04, Romain Izard wrote:\n> The atmel serial port driver reported the following warning on suspend:\n> atmel_usart f8020000.serial: ttyS1: Unable to drain transmitter\n> \n> As the ATMEL_US_TXEMPTY status bit in ATMEL_US_CSR is always cleared\n> when the transmitter is disabled, we need to know the transmitter's\n> state to return the real fifo state. And as ATMEL_US_CR is write-only,\n> it is necessary to save the state of the transmitter in a local\n> variable, and update the variable when TXEN and TXDIS is written in\n> ATMEL_US_CR.\n> \n> After those changes, atmel_tx_empty can return \"empty\" on suspend, the\n> warning in uart_suspend_port disappears, and suspending is 20ms shorter\n> for each enabled Atmel serial port.\n> \n> Signed-off-by: Romain Izard \n> ---\n> drivers/tty/serial/atmel_serial.c | 14 ++++++++++++++\n> 1 file changed, 14 insertions(+)\n> \n> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c\n> index 7551cab438ff..783af6648be0 100644\n> --- a/drivers/tty/serial/atmel_serial.c\n> +++ b/drivers/tty/serial/atmel_serial.c\n> @@ -171,6 +171,7 @@ struct atmel_uart_port {\n> \tbool\t\t\thas_hw_timer;\n> \tstruct timer_list\tuart_timer;\n> \n> +\tbool\t\t\ttx_stopped;\n> \tbool\t\t\tsuspended;\n> \tunsigned int\t\tpending;\n> \tunsigned int\t\tpending_status;\n> @@ -380,6 +381,10 @@ static int atmel_config_rs485(struct uart_port *port,\n> */\n> static u_int atmel_tx_empty(struct uart_port *port)\n> {\n> +\tstruct atmel_uart_port *atmel_port = to_atmel_uart_port(port);\n> +\n> +\tif (atmel_port->tx_stopped)\n> +\t\treturn TIOCSER_TEMT;\n> \treturn (atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXEMPTY) ?\n> \t\tTIOCSER_TEMT :\n> \t\t0;\n> @@ -485,6 +490,7 @@ static void atmel_stop_tx(struct uart_port *port)\n> \t * is fully transmitted.\n> \t */\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS);\n> +\tatmel_port->tx_stopped = true;\n> \n> \t/* Disable interrupts */\n> \tatmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);\n> @@ -492,6 +498,7 @@ static void atmel_stop_tx(struct uart_port *port)\n> \tif ((port->rs485.flags & SER_RS485_ENABLED) &&\n> \t !(port->rs485.flags & SER_RS485_RX_DURING_TX))\n> \t\tatmel_start_rx(port);\n> +\n> }\nThis line feed is not needed.\nOtherwise,\n\nAcked-by: Richard Genoud \n\n> \n> /*\n> @@ -521,6 +528,7 @@ static void atmel_start_tx(struct uart_port *port)\n> \n> \t/* re-enable the transmitter */\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN);\n> +\tatmel_port->tx_stopped = false;\n> }\n> \n> /*\n> @@ -1866,6 +1874,7 @@ static int atmel_startup(struct uart_port *port)\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);\n> \t/* enable xmit & rcvr */\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);\n> +\tatmel_port->tx_stopped = false;\n> \n> \tsetup_timer(&atmel_port->uart_timer,\n> \t\t\tatmel_uart_timer_callback,\n> @@ -2122,6 +2131,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,\n> \n> \t/* disable receiver and transmitter */\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXDIS);\n> +\tatmel_port->tx_stopped = true;\n> \n> \t/* mode */\n> \tif (port->rs485.flags & SER_RS485_ENABLED) {\n> @@ -2207,6 +2217,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,\n> \tatmel_uart_writel(port, ATMEL_US_BRGR, quot);\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);\n> +\tatmel_port->tx_stopped = false;\n> \n> \t/* restore interrupts */\n> \tatmel_uart_writel(port, ATMEL_US_IER, imr);\n> @@ -2450,6 +2461,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count)\n> \n> \t/* Make sure that tx path is actually able to send characters */\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN);\n> +\tatmel_port->tx_stopped = false;\n> \n> \tuart_console_write(port, s, count, atmel_console_putchar);\n> \n> @@ -2511,6 +2523,7 @@ static int __init atmel_console_setup(struct console *co, char *options)\n> {\n> \tint ret;\n> \tstruct uart_port *port = &atmel_ports[co->index].uart;\n> +\tstruct atmel_uart_port *atmel_port = to_atmel_uart_port(port);\n> \tint baud = 115200;\n> \tint bits = 8;\n> \tint parity = 'n';\n> @@ -2528,6 +2541,7 @@ static int __init atmel_console_setup(struct console *co, char *options)\n> \tatmel_uart_writel(port, ATMEL_US_IDR, -1);\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);\n> \tatmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);\n> +\tatmel_port->tx_stopped = false;\n> \n> \tif (options)\n> \t\tuart_parse_options(options, &baud, &parity, &bits, &flow);\n> \n\n--\nTo unsubscribe from this list: send the line \"unsubscribe linux-pwm\" in\nthe body of a message to majordomo@vger.kernel.org\nMore majordomo info at http://vger.kernel.org/majordomo-info.html","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; 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Linux x86_64; rv:52.0) Gecko/20100101\n\tThunderbird/52.3.0","MIME-Version":"1.0","In-Reply-To":"<20170915140411.31716-10-romain.izard.pro@gmail.com>","Content-Type":"text/plain; charset=utf-8","Content-Language":"fr","Content-Transfer-Encoding":"7bit","Sender":"linux-pwm-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"linux-pwm@vger.kernel.org"}}]