From: Martin Aberg <mab...@gaisler.com>
The APBUART control register can be updated from both ISR and task context so
the device must be locked when manipulating the register.
There is also a scenario with RX FIFO interrupts where a few characters can be
in the FIFO without generating interrupt.
---
c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c | 64 +++++++++++++++++------
1 file changed, 48 insertions(+), 16 deletions(-)
diff --git a/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
b/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
index 379d9ff..28066a3 100644
--- a/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
+++ b/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
@@ -358,8 +358,8 @@ static int apbuart_info(
if (priv->mode == TERMIOS_POLLED)
str1 = "TERMIOS_POLLED";
- else if (priv->mode == TERMIOS_TASK_DRIVEN)
- str1 = "TERMIOS_TASK_DRIVEN";
+ else if (priv->mode == TERMIOS_IRQ_DRIVEN)
+ str1 = "TERMIOS_IRQ_DRIVEN";
else if (priv->mode == TERMIOS_TASK_DRIVEN)
str1 = "TERMIOS_TASK_DRIVEN";
else
@@ -489,7 +489,8 @@ static void last_close(
if (uart->mode != TERMIOS_POLLED) {
/* Turn off RX interrupts */
rtems_termios_device_lock_acquire(base, &lock_context);
- uart->regs->ctrl &= ~(APBUART_CTRL_RI | APBUART_CTRL_RF);
+ uart->regs->ctrl &=
+ ~(APBUART_CTRL_DI | APBUART_CTRL_RI | APBUART_CTRL_RF);
rtems_termios_device_lock_release(base, &lock_context);
/**** Flush device ****/
@@ -515,29 +516,50 @@ static int read_polled(rtems_termios_device_context *base)
return apbuart_inbyte_nonblocking(uart->regs);
}
+/* This function is called from TERMIOS rxdaemon task without device lock. */
static int read_task(rtems_termios_device_context *base)
{
+ rtems_interrupt_lock_context lock_context;
struct apbuart_priv *uart = base_get_priv(base);
- int c, tot;
- char buf[32];
+ struct apbuart_regs *regs = uart->regs;
+ int cnt;
+ char buf[33];
struct rtems_termios_tty *tty;
+ uint32_t ctrl_add;
+ ctrl_add = APBUART_CTRL_RI;
+ if (uart->cap & CAP_DI) {
+ ctrl_add |= (APBUART_CTRL_DI | APBUART_CTRL_RF);
+ }
tty = uart->tty;
- tot = 0;
- while ((c=apbuart_inbyte_nonblocking(uart->regs)) != EOF) {
- buf[tot] = c;
- tot++;
- if (tot > 31) {
- rtems_termios_enqueue_raw_characters(tty, buf, tot);
- tot = 0;
+ do {
+ cnt = 0;
+ while (
+ (regs->status & APBUART_STATUS_DR) &&
+ (cnt < sizeof(buf))
+ ) {
+ buf[cnt] = regs->data;
+ cnt++;
+ }
+ if (0 < cnt) {
+ /* Tell termios layer about new characters */
+ rtems_termios_enqueue_raw_characters(tty, &buf[0], cnt);
}
- }
- if (tot > 0)
- rtems_termios_enqueue_raw_characters(tty, buf, tot);
+
+ /*
+ * Turn on RX interrupts. A new character in FIFO now may not
+ * cause interrupt so we must check data ready again
+ * afterwards.
+ */
+ rtems_termios_device_lock_acquire(base, &lock_context);
+ regs->ctrl |= ctrl_add;
+ rtems_termios_device_lock_release(base, &lock_context);
+ } while (regs->status & APBUART_STATUS_DR);
return EOF;
}
+
struct apbuart_baud {
unsigned int num;
unsigned int baud;
@@ -779,6 +801,7 @@ static void write_interrupt(
static void apbuart_cons_isr(void *arg)
{
rtems_termios_tty *tty = arg;
+ rtems_termios_device_context *base;
struct console_dev *condev = rtems_termios_get_device_context(tty);
struct apbuart_priv *uart = condev_get_priv(condev);
struct apbuart_regs *regs = uart->regs;
@@ -787,7 +810,16 @@ static void apbuart_cons_isr(void *arg)
int cnt;
if (uart->mode == TERMIOS_TASK_DRIVEN) {
- if ((status=regs->status) & APBUART_STATUS_DR) {
+ if ((status = regs->status) & APBUART_STATUS_DR) {
+ rtems_interrupt_lock_context lock_context;
+
+ /* Turn off RX interrupts */
+ base = rtems_termios_get_device_context(tty);
+ rtems_termios_device_lock_acquire(base, &lock_context);
+ regs->ctrl &=
+ ~(APBUART_CTRL_DI | APBUART_CTRL_RI |
+ APBUART_CTRL_RF);
+ rtems_termios_device_lock_release(base, &lock_context);
/* Activate termios RX daemon task */
rtems_termios_rxirq_occured(tty);
}
--
2.7.4
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