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Patch from Eric Norum <eric@cls.usask.ca> to avoid lockup under

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the correct circumstances of DMA buffer size, serial
line interrupts, and ethernet interrupts the termios osend routine would
lock up waiting for the raw output buffer semaphore.
This commit is contained in:
Joel Sherrill
2000-08-01 15:23:59 +00:00
parent 1611244202
commit e6890ba1f5
3 changed files with 27 additions and 27 deletions
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18
c/src/exec/libcsupport/src/termios.c
View File

@@ -126,7 +126,7 @@ struct rtems_termios_tty {
volatile unsigned int rawOutBufHead;
volatile unsigned int rawOutBufTail;
rtems_id rawOutBufSemaphore;
enum {rob_idle, rob_busy, rob_wait } rawOutBufState;
volatile enum {rob_idle, rob_busy, rob_wait } rawOutBufState;
/*
* Callbacks to device-specific routines
@@ -219,7 +219,7 @@ rtems_termios_open (
sc = rtems_semaphore_create (
rtems_build_name ('T', 'R', 'x', c),
0,
RTEMS_COUNTING_SEMAPHORE | RTEMS_PRIORITY,
RTEMS_SIMPLE_BINARY_SEMAPHORE | RTEMS_FIFO,
RTEMS_NO_PRIORITY,
&tty->rawOutBufSemaphore);
if (sc != RTEMS_SUCCESSFUL)
@@ -531,7 +531,7 @@ osend (const char *buf, int len, struct rtems_termios_tty *tty)
if (tty->rawOutBufState == rob_idle) {
/* check, whether XOFF has been received */
if (!(tty->flow_ctrl & FL_ORCVXOF)) {
(*tty->device.write)(tty->minor,
(*tty->device.write)(tty->minor,
(char *)&tty->rawOutBuf[tty->rawOutBufTail],1);
}
else {
@@ -1101,8 +1101,10 @@ rtems_termios_dequeue_characters (void *ttyp, int len)
else {
if (tty->rawOutBufState == rob_wait)
rtems_semaphore_release (tty->rawOutBufSemaphore);
if ( tty->rawOutBufHead == tty->rawOutBufTail )
if ( tty->rawOutBufHead == tty->rawOutBufTail ) {
tty->rawOutBufState = rob_idle;
return 0;
}
newTail = (tty->rawOutBufTail + len) % RAW_OUTPUT_BUFFER_SIZE;
if (newTail == tty->rawOutBufHead) {
/*
@@ -1117,6 +1119,7 @@ rtems_termios_dequeue_characters (void *ttyp, int len)
/* Buffer not empty, but output stops due to XOFF */
/* set flag, that output has been stopped */
tty->flow_ctrl |= FL_OSTOP;
tty->rawOutBufState = rob_busy;
nToSend = 0;
}
else {
@@ -1130,15 +1133,12 @@ rtems_termios_dequeue_characters (void *ttyp, int len)
/* when flow control XON or XOF, don't send blocks of data */
/* to allow fast reaction on incoming flow ctrl and low latency*/
/* for outgoing flow control */
if (tty->flow_ctrl & (FL_MDXON | FL_MDXOF)) {
if (tty->flow_ctrl & (FL_MDXON | FL_MDXOF))
nToSend = 1;
}
(*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[newTail], nToSend);
tty->rawOutBufState = rob_busy;
(*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[newTail], nToSend);
}
tty->rawOutBufTail = newTail;
}
return nToSend;
}

18
c/src/lib/libc/termios.c
View File

@@ -126,7 +126,7 @@ struct rtems_termios_tty {
volatile unsigned int rawOutBufHead;
volatile unsigned int rawOutBufTail;
rtems_id rawOutBufSemaphore;
enum {rob_idle, rob_busy, rob_wait } rawOutBufState;
volatile enum {rob_idle, rob_busy, rob_wait } rawOutBufState;
/*
* Callbacks to device-specific routines
@@ -219,7 +219,7 @@ rtems_termios_open (
sc = rtems_semaphore_create (
rtems_build_name ('T', 'R', 'x', c),
0,
RTEMS_COUNTING_SEMAPHORE | RTEMS_PRIORITY,
RTEMS_SIMPLE_BINARY_SEMAPHORE | RTEMS_FIFO,
RTEMS_NO_PRIORITY,
&tty->rawOutBufSemaphore);
if (sc != RTEMS_SUCCESSFUL)
@@ -531,7 +531,7 @@ osend (const char *buf, int len, struct rtems_termios_tty *tty)
if (tty->rawOutBufState == rob_idle) {
/* check, whether XOFF has been received */
if (!(tty->flow_ctrl & FL_ORCVXOF)) {
(*tty->device.write)(tty->minor,
(*tty->device.write)(tty->minor,
(char *)&tty->rawOutBuf[tty->rawOutBufTail],1);
}
else {
@@ -1101,8 +1101,10 @@ rtems_termios_dequeue_characters (void *ttyp, int len)
else {
if (tty->rawOutBufState == rob_wait)
rtems_semaphore_release (tty->rawOutBufSemaphore);
if ( tty->rawOutBufHead == tty->rawOutBufTail )
if ( tty->rawOutBufHead == tty->rawOutBufTail ) {
tty->rawOutBufState = rob_idle;
return 0;
}
newTail = (tty->rawOutBufTail + len) % RAW_OUTPUT_BUFFER_SIZE;
if (newTail == tty->rawOutBufHead) {
/*
@@ -1117,6 +1119,7 @@ rtems_termios_dequeue_characters (void *ttyp, int len)
/* Buffer not empty, but output stops due to XOFF */
/* set flag, that output has been stopped */
tty->flow_ctrl |= FL_OSTOP;
tty->rawOutBufState = rob_busy;
nToSend = 0;
}
else {
@@ -1130,15 +1133,12 @@ rtems_termios_dequeue_characters (void *ttyp, int len)
/* when flow control XON or XOF, don't send blocks of data */
/* to allow fast reaction on incoming flow ctrl and low latency*/
/* for outgoing flow control */
if (tty->flow_ctrl & (FL_MDXON | FL_MDXOF)) {
if (tty->flow_ctrl & (FL_MDXON | FL_MDXOF))
nToSend = 1;
}
(*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[newTail], nToSend);
tty->rawOutBufState = rob_busy;
(*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[newTail], nToSend);
}
tty->rawOutBufTail = newTail;
}
return nToSend;
}

18
cpukit/libcsupport/src/termios.c
View File

@@ -126,7 +126,7 @@ struct rtems_termios_tty {
volatile unsigned int rawOutBufHead;
volatile unsigned int rawOutBufTail;
rtems_id rawOutBufSemaphore;
enum {rob_idle, rob_busy, rob_wait } rawOutBufState;
volatile enum {rob_idle, rob_busy, rob_wait } rawOutBufState;
/*
* Callbacks to device-specific routines
@@ -219,7 +219,7 @@ rtems_termios_open (
sc = rtems_semaphore_create (
rtems_build_name ('T', 'R', 'x', c),
0,
RTEMS_COUNTING_SEMAPHORE | RTEMS_PRIORITY,
RTEMS_SIMPLE_BINARY_SEMAPHORE | RTEMS_FIFO,
RTEMS_NO_PRIORITY,
&tty->rawOutBufSemaphore);
if (sc != RTEMS_SUCCESSFUL)
@@ -531,7 +531,7 @@ osend (const char *buf, int len, struct rtems_termios_tty *tty)
if (tty->rawOutBufState == rob_idle) {
/* check, whether XOFF has been received */
if (!(tty->flow_ctrl & FL_ORCVXOF)) {
(*tty->device.write)(tty->minor,
(*tty->device.write)(tty->minor,
(char *)&tty->rawOutBuf[tty->rawOutBufTail],1);
}
else {
@@ -1101,8 +1101,10 @@ rtems_termios_dequeue_characters (void *ttyp, int len)
else {
if (tty->rawOutBufState == rob_wait)
rtems_semaphore_release (tty->rawOutBufSemaphore);
if ( tty->rawOutBufHead == tty->rawOutBufTail )
if ( tty->rawOutBufHead == tty->rawOutBufTail ) {
tty->rawOutBufState = rob_idle;
return 0;
}
newTail = (tty->rawOutBufTail + len) % RAW_OUTPUT_BUFFER_SIZE;
if (newTail == tty->rawOutBufHead) {
/*
@@ -1117,6 +1119,7 @@ rtems_termios_dequeue_characters (void *ttyp, int len)
/* Buffer not empty, but output stops due to XOFF */
/* set flag, that output has been stopped */
tty->flow_ctrl |= FL_OSTOP;
tty->rawOutBufState = rob_busy;
nToSend = 0;
}
else {
@@ -1130,15 +1133,12 @@ rtems_termios_dequeue_characters (void *ttyp, int len)
/* when flow control XON or XOF, don't send blocks of data */
/* to allow fast reaction on incoming flow ctrl and low latency*/
/* for outgoing flow control */
if (tty->flow_ctrl & (FL_MDXON | FL_MDXOF)) {
if (tty->flow_ctrl & (FL_MDXON | FL_MDXOF))
nToSend = 1;
}
(*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[newTail], nToSend);
tty->rawOutBufState = rob_busy;
(*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[newTail], nToSend);
}
tty->rawOutBufTail = newTail;
}
return nToSend;
}