diff options
| -rw-r--r-- | drivers/serial/sh-sci.c | 114 |
1 files changed, 81 insertions, 33 deletions
diff --git a/drivers/serial/sh-sci.c b/drivers/serial/sh-sci.c index cd52dd64edf..304a877d083 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); } |