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Diffstat (limited to 'arch/mn10300/kernel/mn10300-serial.c')
-rw-r--r--arch/mn10300/kernel/mn10300-serial.c121
1 files changed, 78 insertions, 43 deletions
diff --git a/arch/mn10300/kernel/mn10300-serial.c b/arch/mn10300/kernel/mn10300-serial.c
index cac0f0da9203..587545cb7e4c 100644
--- a/arch/mn10300/kernel/mn10300-serial.c
+++ b/arch/mn10300/kernel/mn10300-serial.c
@@ -444,25 +444,53 @@ struct mn10300_serial_int mn10300_serial_int_tbl[NR_IRQS];
static void mn10300_serial_dis_tx_intr(struct mn10300_serial_port *port)
{
- unsigned long flags;
+ int retries = 100;
u16 x;
- flags = arch_local_cli_save();
- *port->tx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
- x = *port->tx_icr;
- arch_local_irq_restore(flags);
+ /* nothing to do if irq isn't set up */
+ if (!mn10300_serial_int_tbl[port->tx_irq].port)
+ return;
+
+ port->tx_flags |= MNSCx_TX_STOP;
+ mb();
+
+ /*
+ * Here we wait for the irq to be disabled. Either it already is
+ * disabled or we wait some number of retries for the VDMA handler
+ * to disable it. The retries give the VDMA handler enough time to
+ * run to completion if it was already in progress. If the VDMA IRQ
+ * is enabled but the handler is not yet running when arrive here,
+ * the STOP flag will prevent the handler from conflicting with the
+ * driver code following this loop.
+ */
+ while ((*port->tx_icr & GxICR_ENABLE) && retries-- > 0)
+ ;
+ if (retries <= 0) {
+ *port->tx_icr =
+ NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
+ x = *port->tx_icr;
+ }
}
static void mn10300_serial_en_tx_intr(struct mn10300_serial_port *port)
{
- unsigned long flags;
u16 x;
- flags = arch_local_cli_save();
+ /* nothing to do if irq isn't set up */
+ if (!mn10300_serial_int_tbl[port->tx_irq].port)
+ return;
+
+ /* stop vdma irq if not already stopped */
+ if (!(port->tx_flags & MNSCx_TX_STOP))
+ mn10300_serial_dis_tx_intr(port);
+
+ port->tx_flags &= ~MNSCx_TX_STOP;
+ mb();
+
*port->tx_icr =
- NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL) | GxICR_ENABLE;
+ NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL) |
+ GxICR_ENABLE | GxICR_REQUEST | GxICR_DETECT;
x = *port->tx_icr;
- arch_local_irq_restore(flags);
}
static void mn10300_serial_dis_rx_intr(struct mn10300_serial_port *port)
@@ -807,8 +835,6 @@ static void mn10300_serial_start_tx(struct uart_port *_port)
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
- u16 x;
-
_enter("%s{%lu}",
port->name,
CIRC_CNT(&port->uart.state->xmit.head,
@@ -816,14 +842,7 @@ static void mn10300_serial_start_tx(struct uart_port *_port)
UART_XMIT_SIZE));
/* kick the virtual DMA controller */
- arch_local_cli();
- x = *port->tx_icr;
- x |= GxICR_ENABLE;
-
- if (*port->_status & SC01STR_TBF)
- x &= ~(GxICR_REQUEST | GxICR_DETECT);
- else
- x |= GxICR_REQUEST | GxICR_DETECT;
+ mn10300_serial_en_tx_intr(port);
_debug("CTR=%04hx ICR=%02hx STR=%04x TMD=%02hx TBR=%04hx ICR=%04hx",
*port->_control, *port->_intr, *port->_status,
@@ -831,10 +850,6 @@ static void mn10300_serial_start_tx(struct uart_port *_port)
(port->div_timer == MNSCx_DIV_TIMER_8BIT) ?
*(volatile u8 *)port->_tmxbr : *port->_tmxbr,
*port->tx_icr);
-
- *port->tx_icr = x;
- x = *port->tx_icr;
- arch_local_sti();
}
/*
@@ -844,13 +859,17 @@ static void mn10300_serial_send_xchar(struct uart_port *_port, char ch)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
+ unsigned long flags;
_enter("%s,%02x", port->name, ch);
if (likely(port->gdbstub)) {
port->tx_xchar = ch;
- if (ch)
+ if (ch) {
+ spin_lock_irqsave(&port->uart.lock, flags);
mn10300_serial_en_tx_intr(port);
+ spin_unlock_irqrestore(&port->uart.lock, flags);
+ }
}
}
@@ -911,18 +930,21 @@ static void mn10300_serial_break_ctl(struct uart_port *_port, int ctl)
{
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
+ unsigned long flags;
_enter("%s,%d", port->name, ctl);
+ spin_lock_irqsave(&port->uart.lock, flags);
if (ctl) {
/* tell the virtual DMA handler to assert BREAK */
- port->tx_break = 1;
+ port->tx_flags |= MNSCx_TX_BREAK;
mn10300_serial_en_tx_intr(port);
} else {
- port->tx_break = 0;
+ port->tx_flags &= ~MNSCx_TX_BREAK;
*port->_control &= ~SC01CTR_BKE;
mn10300_serial_en_tx_intr(port);
}
+ spin_unlock_irqrestore(&port->uart.lock, flags);
}
/*
@@ -945,6 +967,7 @@ static int mn10300_serial_startup(struct uart_port *_port)
return -ENOMEM;
port->rx_inp = port->rx_outp = 0;
+ port->tx_flags = 0;
/* finally, enable the device */
*port->_intr = SC01ICR_TI;
@@ -994,14 +1017,22 @@ error:
*/
static void mn10300_serial_shutdown(struct uart_port *_port)
{
+ unsigned long flags;
u16 x;
struct mn10300_serial_port *port =
container_of(_port, struct mn10300_serial_port, uart);
_enter("%s", port->name);
+ spin_lock_irqsave(&_port->lock, flags);
+ mn10300_serial_dis_tx_intr(port);
+
+ *port->rx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
+ x = *port->rx_icr;
+ port->tx_flags = 0;
+ spin_unlock_irqrestore(&_port->lock, flags);
+
/* disable the serial port and its baud rate timer */
- port->tx_break = 0;
*port->_control &= ~(SC01CTR_TXE | SC01CTR_RXE | SC01CTR_BKE);
*port->_tmxmd = 0;
@@ -1016,12 +1047,8 @@ static void mn10300_serial_shutdown(struct uart_port *_port)
free_irq(port->rx_irq, port);
free_irq(port->tx_irq, port);
- arch_local_cli();
- *port->rx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
- x = *port->rx_icr;
- *port->tx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
- x = *port->tx_icr;
- arch_local_sti();
+ mn10300_serial_int_tbl[port->tx_irq].port = NULL;
+ mn10300_serial_int_tbl[port->rx_irq].port = NULL;
}
/*
@@ -1549,17 +1576,24 @@ static void mn10300_serial_console_write(struct console *co,
{
struct mn10300_serial_port *port;
unsigned i;
- u16 scxctr, txicr, tmp;
+ u16 scxctr;
u8 tmxmd;
+ unsigned long flags;
+ int locked = 1;
port = mn10300_serial_ports[co->index];
+ local_irq_save(flags);
+ if (port->uart.sysrq) {
+ /* mn10300_serial_interrupt() already took the lock */
+ locked = 0;
+ } else if (oops_in_progress) {
+ locked = spin_trylock(&port->uart.lock);
+ } else
+ spin_lock(&port->uart.lock);
+
/* firstly hijack the serial port from the "virtual DMA" controller */
- arch_local_cli();
- txicr = *port->tx_icr;
- *port->tx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
- tmp = *port->tx_icr;
- arch_local_sti();
+ mn10300_serial_dis_tx_intr(port);
/* the transmitter may be disabled */
scxctr = *port->_control;
@@ -1613,10 +1647,11 @@ static void mn10300_serial_console_write(struct console *co,
if (!(scxctr & SC01CTR_TXE))
*port->_control = scxctr;
- arch_local_cli();
- *port->tx_icr = txicr;
- tmp = *port->tx_icr;
- arch_local_sti();
+ mn10300_serial_en_tx_intr(port);
+
+ if (locked)
+ spin_unlock(&port->uart.lock);
+ local_irq_restore(flags);
}
/*
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 01:36:51 +0000