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path: root/drivers/tty/serial/sh-sci.c
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Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
-rw-r--r--drivers/tty/serial/sh-sci.c88
1 files changed, 67 insertions, 21 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 5b50c792ad5f..e7d6566fafaf 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -844,14 +844,32 @@ static int sci_handle_fifo_overrun(struct uart_port *port)
struct tty_port *tport = &port->state->port;
struct sci_port *s = to_sci_port(port);
struct plat_sci_reg *reg;
- int copied = 0;
+ int copied = 0, offset;
+ u16 status, bit;
+
+ switch (port->type) {
+ case PORT_SCIF:
+ case PORT_HSCIF:
+ offset = SCLSR;
+ break;
+ case PORT_SCIFA:
+ case PORT_SCIFB:
+ offset = SCxSR;
+ break;
+ default:
+ return 0;
+ }
- reg = sci_getreg(port, SCLSR);
+ reg = sci_getreg(port, offset);
if (!reg->size)
return 0;
- if ((serial_port_in(port, SCLSR) & (1 << s->overrun_bit))) {
- serial_port_out(port, SCLSR, 0);
+ status = serial_port_in(port, offset);
+ bit = 1 << s->overrun_bit;
+
+ if (status & bit) {
+ status &= ~bit;
+ serial_port_out(port, offset, status);
port->icount.overrun++;
@@ -996,16 +1014,24 @@ static inline unsigned long port_rx_irq_mask(struct uart_port *port)
static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
{
- unsigned short ssr_status, scr_status, err_enabled;
- unsigned short slr_status = 0;
+ unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
struct uart_port *port = ptr;
struct sci_port *s = to_sci_port(port);
irqreturn_t ret = IRQ_NONE;
ssr_status = serial_port_in(port, SCxSR);
scr_status = serial_port_in(port, SCSCR);
- if (port->type == PORT_SCIF || port->type == PORT_HSCIF)
- slr_status = serial_port_in(port, SCLSR);
+ switch (port->type) {
+ case PORT_SCIF:
+ case PORT_HSCIF:
+ orer_status = serial_port_in(port, SCLSR);
+ break;
+ case PORT_SCIFA:
+ case PORT_SCIFB:
+ orer_status = ssr_status;
+ break;
+ }
+
err_enabled = scr_status & port_rx_irq_mask(port);
/* Tx Interrupt */
@@ -1033,10 +1059,8 @@ static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
ret = sci_br_interrupt(irq, ptr);
/* Overrun Interrupt */
- if (port->type == PORT_SCIF || port->type == PORT_HSCIF) {
- if (slr_status & 0x01)
- sci_handle_fifo_overrun(port);
- }
+ if (orer_status & (1 << s->overrun_bit))
+ sci_handle_fifo_overrun(port);
return ret;
}
@@ -1967,18 +1991,40 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
#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
+ * Calculate delay for 2 DMA buffers (4 FIFO).
+ * 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.
+ * Then below we calculate 5 jiffies (20ms) for 2 DMA buffers (4 FIFO
+ * sizes), but when performing a faster transfer, value obtained by
+ * this formula is may not enough. Therefore, if value is smaller than
+ * 20msec, this sets 20msec as timeout of DMA.
*/
if (s->chan_rx) {
- s->rx_timeout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 /
- port->fifosize / 2;
+ unsigned int bits;
+
+ /* byte size and parity */
+ switch (termios->c_cflag & CSIZE) {
+ case CS5:
+ bits = 7;
+ break;
+ case CS6:
+ bits = 8;
+ break;
+ case CS7:
+ bits = 9;
+ break;
+ default:
+ bits = 10;
+ break;
+ }
+
+ if (termios->c_cflag & CSTOPB)
+ bits++;
+ if (termios->c_cflag & PARENB)
+ bits++;
+ s->rx_timeout = DIV_ROUND_UP((s->buf_len_rx * 2 * bits * HZ) /
+ (baud / 10), 10);
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))