From 81ca8e8286c48df22eb798879d99aabac663b5f1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Fri, 2 Mar 2018 11:07:27 +0100 Subject: serial: imx: Also enable the aging timer in PIO mode MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This allows to increase the RX waterlevel which allows to delay the RRDY irq. The desired effect is that less irqs are needed to handle characters and so reduce irq count of the system. Signed-off-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/imx.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'drivers/tty/serial') diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 3c1bfe8..e1f00d5 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -418,6 +418,7 @@ static void imx_start_rx(struct uart_port *port) ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN; } else { ucr1 |= UCR1_RRDYEN; + ucr2 |= UCR2_ATEN; } /* Write UCR2 first as it includes RXEN */ @@ -472,6 +473,7 @@ static void imx_stop_rx(struct uart_port *port) ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN); } else { ucr1 &= ~UCR1_RRDYEN; + ucr2 &= ~UCR2_ATEN; } imx_uart_writel(sport, ucr1, UCR1); @@ -1393,6 +1395,10 @@ static int imx_startup(struct uart_port *port) ucr1 = imx_uart_readl(sport, UCR1); ucr1 |= UCR1_RRDYEN; imx_uart_writel(sport, ucr1, UCR1); + + ucr2 = imx_uart_readl(sport, UCR2); + ucr2 |= UCR2_ATEN; + imx_uart_writel(sport, ucr2, UCR2); } spin_unlock_irqrestore(&sport->port.lock, flags); @@ -1424,7 +1430,7 @@ static void imx_shutdown(struct uart_port *port) spin_lock_irqsave(&sport->port.lock, flags); ucr2 = imx_uart_readl(sport, UCR2); - ucr2 &= ~UCR2_TXEN; + ucr2 &= ~(UCR2_TXEN | UCR2_ATEN); imx_uart_writel(sport, ucr2, UCR2); spin_unlock_irqrestore(&sport->port.lock, flags); @@ -1613,13 +1619,14 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios, imx_uart_writel(sport, old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN), UCR1); + old_ucr2 = imx_uart_readl(sport, UCR2); + imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2); while (!(imx_uart_readl(sport, USR2) & USR2_TXDC)) barrier(); /* then, disable everything */ - old_ucr2 = imx_uart_readl(sport, UCR2); - imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN), UCR2); + imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2); old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN); /* custom-baudrate handling */ @@ -1750,12 +1757,14 @@ static int imx_poll_init(struct uart_port *port) ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN); ucr2 |= UCR2_RXEN; + ucr2 &= ~UCR2_ATEN; imx_uart_writel(sport, ucr1, UCR1); imx_uart_writel(sport, ucr2, UCR2); /* now enable irqs */ imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1); + imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2); spin_unlock_irqrestore(&sport->port.lock, flags); -- cgit v1.1