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Diffstat (limited to 'drivers/serial')
-rw-r--r--drivers/serial/sh-sci.c114
1 files changed, 81 insertions, 33 deletions
diff --git a/drivers/serial/sh-sci.c b/drivers/serial/sh-sci.c
index cd52dd64edf0..304a877d083d 100644
--- a/drivers/serial/sh-sci.c
+++ b/drivers/serial/sh-sci.c
@@ -106,6 +106,7 @@ struct sci_port {
struct work_struct work_tx;
struct work_struct work_rx;
struct timer_list rx_timer;
+ unsigned int rx_timeout;
#endif
};
@@ -673,22 +674,22 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
struct sci_port *s = to_sci_port(port);
if (s->chan_rx) {
- unsigned long tout;
u16 scr = sci_in(port, SCSCR);
u16 ssr = sci_in(port, SCxSR);
/* Disable future Rx interrupts */
- sci_out(port, SCSCR, scr & ~SCI_CTRL_FLAGS_RIE);
+ if (port->type == PORT_SCIFA) {
+ disable_irq_nosync(irq);
+ scr |= 0x4000;
+ } else {
+ scr &= ~SCI_CTRL_FLAGS_RIE;
+ }
+ sci_out(port, SCSCR, scr);
/* Clear current interrupt */
sci_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port)));
- /* Calculate delay for 1.5 DMA buffers */
- tout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 /
- port->fifosize / 2;
- dev_dbg(port->dev, "Rx IRQ: setup timeout in %lu ms\n",
- tout * 1000 / HZ);
- if (tout < 2)
- tout = 2;
- mod_timer(&s->rx_timer, jiffies + tout);
+ dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
+ jiffies, s->rx_timeout);
+ mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
return IRQ_HANDLED;
}
@@ -925,13 +926,17 @@ static void sci_dma_tx_complete(void *arg)
s->cookie_tx = -EINVAL;
s->desc_tx = NULL;
- spin_unlock_irqrestore(&port->lock, flags);
-
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
- if (uart_circ_chars_pending(xmit))
+ if (!uart_circ_empty(xmit)) {
schedule_work(&s->work_tx);
+ } else if (port->type == PORT_SCIFA) {
+ u16 ctrl = sci_in(port, SCSCR);
+ sci_out(port, SCSCR, ctrl & ~SCI_CTRL_FLAGS_TIE);
+ }
+
+ spin_unlock_irqrestore(&port->lock, flags);
}
/* Locking: called with port lock held */
@@ -975,13 +980,13 @@ static void sci_dma_rx_complete(void *arg)
unsigned long flags;
int count;
- dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
+ dev_dbg(port->dev, "%s(%d) active #%d\n", __func__, port->line, s->active_rx);
spin_lock_irqsave(&port->lock, flags);
count = sci_dma_rx_push(s, tty, s->buf_len_rx);
- mod_timer(&s->rx_timer, jiffies + msecs_to_jiffies(5));
+ mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
spin_unlock_irqrestore(&port->lock, flags);
@@ -1053,6 +1058,8 @@ static void sci_submit_rx(struct sci_port *s)
sci_rx_dma_release(s, true);
return;
}
+ dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
+ s->cookie_rx[i], i);
}
s->active_rx = s->cookie_rx[0];
@@ -1110,10 +1117,10 @@ static void work_fn_rx(struct work_struct *work)
return;
}
- dev_dbg(port->dev, "%s: cookie %d #%d\n", __func__,
- s->cookie_rx[new], new);
-
s->active_rx = s->cookie_rx[!new];
+
+ dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", __func__,
+ s->cookie_rx[new], new, s->active_rx);
}
static void work_fn_tx(struct work_struct *work)
@@ -1175,23 +1182,28 @@ static void work_fn_tx(struct work_struct *work)
static void sci_start_tx(struct uart_port *port)
{
+ struct sci_port *s = to_sci_port(port);
unsigned short ctrl;
#ifdef CONFIG_SERIAL_SH_SCI_DMA
- struct sci_port *s = to_sci_port(port);
-
- if (s->chan_tx) {
- if (!uart_circ_empty(&s->port.state->xmit) && s->cookie_tx < 0)
- schedule_work(&s->work_tx);
-
- return;
+ if (port->type == PORT_SCIFA) {
+ u16 new, scr = sci_in(port, SCSCR);
+ if (s->chan_tx)
+ new = scr | 0x8000;
+ else
+ new = scr & ~0x8000;
+ if (new != scr)
+ sci_out(port, SCSCR, new);
}
+ if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
+ s->cookie_tx < 0)
+ schedule_work(&s->work_tx);
#endif
-
- /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
- ctrl = sci_in(port, SCSCR);
- ctrl |= SCI_CTRL_FLAGS_TIE;
- sci_out(port, SCSCR, ctrl);
+ if (!s->chan_tx || port->type == PORT_SCIFA) {
+ /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
+ ctrl = sci_in(port, SCSCR);
+ sci_out(port, SCSCR, ctrl | SCI_CTRL_FLAGS_TIE);
+ }
}
static void sci_stop_tx(struct uart_port *port)
@@ -1200,6 +1212,8 @@ static void sci_stop_tx(struct uart_port *port)
/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
ctrl = sci_in(port, SCSCR);
+ if (port->type == PORT_SCIFA)
+ ctrl &= ~0x8000;
ctrl &= ~SCI_CTRL_FLAGS_TIE;
sci_out(port, SCSCR, ctrl);
}
@@ -1210,6 +1224,8 @@ static void sci_start_rx(struct uart_port *port)
/* Set RIE (Receive Interrupt Enable) bit in SCSCR */
ctrl |= sci_in(port, SCSCR);
+ if (port->type == PORT_SCIFA)
+ ctrl &= ~0x4000;
sci_out(port, SCSCR, ctrl);
}
@@ -1219,6 +1235,8 @@ static void sci_stop_rx(struct uart_port *port)
/* Clear RIE (Receive Interrupt Enable) bit in SCSCR */
ctrl = sci_in(port, SCSCR);
+ if (port->type == PORT_SCIFA)
+ ctrl &= ~0x4000;
ctrl &= ~(SCI_CTRL_FLAGS_RIE | SCI_CTRL_FLAGS_REIE);
sci_out(port, SCSCR, ctrl);
}
@@ -1253,8 +1271,12 @@ static void rx_timer_fn(unsigned long arg)
{
struct sci_port *s = (struct sci_port *)arg;
struct uart_port *port = &s->port;
-
u16 scr = sci_in(port, SCSCR);
+
+ if (port->type == PORT_SCIFA) {
+ scr &= ~0x4000;
+ enable_irq(s->irqs[1]);
+ }
sci_out(port, SCSCR, scr | SCI_CTRL_FLAGS_RIE);
dev_dbg(port->dev, "DMA Rx timed out\n");
schedule_work(&s->work_rx);
@@ -1404,8 +1426,12 @@ static void sci_shutdown(struct uart_port *port)
static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+ struct sci_port *s = to_sci_port(port);
+#endif
unsigned int status, baud, smr_val, max_baud;
int t = -1;
+ u16 scfcr = 0;
/*
* earlyprintk comes here early on with port->uartclk set to zero.
@@ -1428,7 +1454,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
sci_out(port, SCSCR, 0x00); /* TE=0, RE=0, CKE1=0 */
if (port->type != PORT_SCI)
- sci_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
+ sci_out(port, SCFCR, scfcr | SCFCR_RFRST | SCFCR_TFRST);
smr_val = sci_in(port, SCSMR) & 3;
if ((termios->c_cflag & CSIZE) == CS7)
@@ -1459,10 +1485,32 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
}
sci_init_pins(port, termios->c_cflag);
- sci_out(port, SCFCR, (termios->c_cflag & CRTSCTS) ? SCFCR_MCE : 0);
+ sci_out(port, SCFCR, scfcr | ((termios->c_cflag & CRTSCTS) ? SCFCR_MCE : 0));
sci_out(port, SCSCR, SCSCR_INIT(port));
+#ifdef CONFIG_SERIAL_SH_SCI_DMA
+ /*
+ * Calculate delay for 1.5 DMA buffers: see
+ * drivers/serial/serial_core.c::uart_update_timeout(). With 10 bits
+ * (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function
+ * calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)."
+ * Then below we calculate 3 jiffies (12ms) for 1.5 DMA buffers (3 FIFO
+ * sizes), but it has been found out experimentally, that this is not
+ * enough: the driver too often needlessly runs on a DMA timeout. 20ms
+ * as a minimum seem to work perfectly.
+ */
+ if (s->chan_rx) {
+ s->rx_timeout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 /
+ port->fifosize / 2;
+ dev_dbg(port->dev,
+ "DMA Rx t-out %ums, tty t-out %u jiffies\n",
+ s->rx_timeout * 1000 / HZ, port->timeout);
+ if (s->rx_timeout < msecs_to_jiffies(20))
+ s->rx_timeout = msecs_to_jiffies(20);
+ }
+#endif
+
if ((termios->c_cflag & CREAD) != 0)
sci_start_rx(port);
}
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-10 18:57:02 +0000