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Message-ID: <1463067456-6983-2-git-send-email-ludovic.desroches@atmel.com>
Date: Thu, 12 May 2016 17:37:35 +0200
From: Ludovic Desroches <ludovic.desroches@...el.com>
To: <nicolas.ferre@...el.com>, <gregkh@...uxfoundation.org>
CC: <jslaby@...e.com>, <linux-serial@...r.kernel.org>,
<linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
Ludovic Desroches <ludovic.desroches@...el.com>
Subject: [PATCH 2/3] tty/serial: atmel: split tx and rx paths
From: Nicolas Ferre <nicolas.ferre@...el.com>
Split TX and RX paths to not schedule RX tasklet on TX events and vice versa.
Signed-off-by: Nicolas Ferre <nicolas.ferre@...el.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@...el.com>
---
drivers/tty/serial/atmel_serial.c | 53 +++++++++++++++++++++++++--------------
1 file changed, 34 insertions(+), 19 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 8854ac6..6c1ec7d 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -145,7 +145,8 @@ struct atmel_uart_port {
dma_cookie_t cookie_rx;
struct scatterlist sg_tx;
struct scatterlist sg_rx;
- struct tasklet_struct tasklet;
+ struct tasklet_struct tasklet_rx;
+ struct tasklet_struct tasklet_tx;
unsigned int irq_status_prev;
unsigned int tx_len;
@@ -708,7 +709,7 @@ static void atmel_rx_chars(struct uart_port *port)
status = atmel_uart_readl(port, ATMEL_US_CSR);
}
- tasklet_schedule(&atmel_port->tasklet);
+ tasklet_schedule(&atmel_port->tasklet_rx);
}
/*
@@ -779,7 +780,7 @@ static void atmel_complete_tx_dma(void *arg)
* remaining data from the beginning of xmit->buf to xmit->head.
*/
if (!uart_circ_empty(xmit))
- tasklet_schedule(&atmel_port->tasklet);
+ tasklet_schedule(&atmel_port->tasklet_tx);
spin_unlock_irqrestore(&port->lock, flags);
}
@@ -964,7 +965,7 @@ static void atmel_complete_rx_dma(void *arg)
struct uart_port *port = arg;
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
- tasklet_schedule(&atmel_port->tasklet);
+ tasklet_schedule(&atmel_port->tasklet_rx);
}
static void atmel_release_rx_dma(struct uart_port *port)
@@ -1004,7 +1005,7 @@ static void atmel_rx_from_dma(struct uart_port *port)
if (dmastat == DMA_ERROR) {
dev_dbg(port->dev, "Get residue error, restart tasklet\n");
atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_TIMEOUT);
- tasklet_schedule(&atmel_port->tasklet);
+ tasklet_schedule(&atmel_port->tasklet_rx);
return;
}
@@ -1158,7 +1159,7 @@ static void atmel_uart_timer_callback(unsigned long data)
struct uart_port *port = (void *)data;
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
- tasklet_schedule(&atmel_port->tasklet);
+ tasklet_schedule(&atmel_port->tasklet_rx);
mod_timer(&atmel_port->uart_timer, jiffies + uart_poll_timeout(port));
}
@@ -1181,7 +1182,7 @@ atmel_handle_receive(struct uart_port *port, unsigned int pending)
if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
atmel_uart_writel(port, ATMEL_US_IDR,
(ATMEL_US_ENDRX | ATMEL_US_TIMEOUT));
- tasklet_schedule(&atmel_port->tasklet);
+ tasklet_schedule(&atmel_port->tasklet_rx);
}
if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
@@ -1193,7 +1194,7 @@ atmel_handle_receive(struct uart_port *port, unsigned int pending)
if (pending & ATMEL_US_TIMEOUT) {
atmel_uart_writel(port, ATMEL_US_IDR,
ATMEL_US_TIMEOUT);
- tasklet_schedule(&atmel_port->tasklet);
+ tasklet_schedule(&atmel_port->tasklet_rx);
}
}
@@ -1223,7 +1224,7 @@ atmel_handle_transmit(struct uart_port *port, unsigned int pending)
/* Either PDC or interrupt transmission */
atmel_uart_writel(port, ATMEL_US_IDR,
atmel_port->tx_done_mask);
- tasklet_schedule(&atmel_port->tasklet);
+ tasklet_schedule(&atmel_port->tasklet_tx);
}
}
@@ -1582,18 +1583,25 @@ static int atmel_prepare_rx_pdc(struct uart_port *port)
/*
* tasklet handling tty stuff outside the interrupt handler.
*/
-static void atmel_tasklet_func(unsigned long data)
+static void atmel_tasklet_rx_func(unsigned long data)
{
struct uart_port *port = (struct uart_port *)data;
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
/* The interrupt handler does not take the lock */
spin_lock(&port->lock);
-
- atmel_port->schedule_tx(port);
-
atmel_port->schedule_rx(port);
+ spin_unlock(&port->lock);
+}
+static void atmel_tasklet_tx_func(unsigned long data)
+{
+ struct uart_port *port = (struct uart_port *)data;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+ /* The interrupt handler does not take the lock */
+ spin_lock(&port->lock);
+ atmel_port->schedule_tx(port);
spin_unlock(&port->lock);
}
@@ -1777,7 +1785,8 @@ static int atmel_startup(struct uart_port *port)
return retval;
}
- tasklet_enable(&atmel_port->tasklet);
+ tasklet_enable(&atmel_port->tasklet_rx);
+ tasklet_enable(&atmel_port->tasklet_tx);
/*
* Initialize DMA (if necessary)
@@ -1906,8 +1915,10 @@ static void atmel_shutdown(struct uart_port *port)
* Clear out any scheduled tasklets before
* we destroy the buffers
*/
- tasklet_disable(&atmel_port->tasklet);
- tasklet_kill(&atmel_port->tasklet);
+ tasklet_disable(&atmel_port->tasklet_rx);
+ tasklet_disable(&atmel_port->tasklet_tx);
+ tasklet_kill(&atmel_port->tasklet_rx);
+ tasklet_kill(&atmel_port->tasklet_tx);
/*
* Ensure everything is stopped and
@@ -2302,9 +2313,12 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
port->irq = pdev->resource[1].start;
port->rs485_config = atmel_config_rs485;
- tasklet_init(&atmel_port->tasklet, atmel_tasklet_func,
+ tasklet_init(&atmel_port->tasklet_rx, atmel_tasklet_rx_func,
+ (unsigned long)port);
+ tasklet_init(&atmel_port->tasklet_tx, atmel_tasklet_tx_func,
(unsigned long)port);
- tasklet_disable(&atmel_port->tasklet);
+ tasklet_disable(&atmel_port->tasklet_rx);
+ tasklet_disable(&atmel_port->tasklet_tx);
memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
@@ -2786,7 +2800,8 @@ static int atmel_serial_remove(struct platform_device *pdev)
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
int ret = 0;
- tasklet_kill(&atmel_port->tasklet);
+ tasklet_kill(&atmel_port->tasklet_rx);
+ tasklet_kill(&atmel_port->tasklet_tx);
device_init_wakeup(&pdev->dev, 0);
--
2.5.0
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