Changeset e6890ba in rtems

Timestamp:

08/01/00 15:23:59 (23 years ago)

Author:

Joel Sherrill <joel.sherrill@…>

Branches:

4.10, 4.11, 4.8, 4.9, 5, master

Children:

4f8473e

Parents:

16112442

Message:

Patch from Eric Norum <eric@…> to avoid lockup under
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.

Files:

• c/src/exec/libcsupport/src/termios.c (modified) (7 diffs)
• c/src/lib/libc/termios.c (modified) (7 diffs)
• cpukit/libcsupport/src/termios.c (modified) (7 diffs)

c/src/exec/libcsupport/src/termios.c

@@ -127 +127 @@
         volatile unsigned int   rawOutBufTail;
         rtems_id                rawOutBufSemaphore;
-        enum {rob_idle, rob_busy, rob_wait }    rawOutBufState;
+        volatile enum {rob_idle, rob_busy, rob_wait }   rawOutBufState;
 
         /*
@@ -220 +220 @@
                         rtems_build_name ('T', 'R', 'x', c),
                         0,
-                        RTEMS_COUNTING_SEMAPHORE | RTEMS_PRIORITY,
+                        RTEMS_SIMPLE_BINARY_SEMAPHORE | RTEMS_FIFO,
                         RTEMS_NO_PRIORITY,
                         &tty->rawOutBufSemaphore);
@@ -532 +532 @@
                   /* 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);
                   }
@@ -1102 +1102 @@
           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) {
@@ -1118 +1120 @@
             /* set flag, that output has been stopped */
             tty->flow_ctrl |= FL_OSTOP;
+            tty->rawOutBufState = rob_busy;
             nToSend = 0;
           }
@@ -1131 +1134 @@
             /* 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->rawOutBufState = rob_busy;
             (*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[newTail], nToSend);
-            tty->rawOutBufState = rob_busy;
           }
           tty->rawOutBufTail = newTail;
@@ -1141 +1143 @@
         return nToSend;
 }
-
-

c/src/lib/libc/termios.c

@@ -127 +127 @@
         volatile unsigned int   rawOutBufTail;
         rtems_id                rawOutBufSemaphore;
-        enum {rob_idle, rob_busy, rob_wait }    rawOutBufState;
+        volatile enum {rob_idle, rob_busy, rob_wait }   rawOutBufState;
 
         /*
@@ -220 +220 @@
                         rtems_build_name ('T', 'R', 'x', c),
                         0,
-                        RTEMS_COUNTING_SEMAPHORE | RTEMS_PRIORITY,
+                        RTEMS_SIMPLE_BINARY_SEMAPHORE | RTEMS_FIFO,
                         RTEMS_NO_PRIORITY,
                         &tty->rawOutBufSemaphore);
@@ -532 +532 @@
                   /* 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);
                   }
@@ -1102 +1102 @@
           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) {
@@ -1118 +1120 @@
             /* set flag, that output has been stopped */
             tty->flow_ctrl |= FL_OSTOP;
+            tty->rawOutBufState = rob_busy;
             nToSend = 0;
           }
@@ -1131 +1134 @@
             /* 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->rawOutBufState = rob_busy;
             (*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[newTail], nToSend);
-            tty->rawOutBufState = rob_busy;
           }
           tty->rawOutBufTail = newTail;
@@ -1141 +1143 @@
         return nToSend;
 }
-
-

cpukit/libcsupport/src/termios.c

@@ -127 +127 @@
         volatile unsigned int   rawOutBufTail;
         rtems_id                rawOutBufSemaphore;
-        enum {rob_idle, rob_busy, rob_wait }    rawOutBufState;
+        volatile enum {rob_idle, rob_busy, rob_wait }   rawOutBufState;
 
         /*
@@ -220 +220 @@
                         rtems_build_name ('T', 'R', 'x', c),
                         0,
-                        RTEMS_COUNTING_SEMAPHORE | RTEMS_PRIORITY,
+                        RTEMS_SIMPLE_BINARY_SEMAPHORE | RTEMS_FIFO,
                         RTEMS_NO_PRIORITY,
                         &tty->rawOutBufSemaphore);
@@ -532 +532 @@
                   /* 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);
                   }
@@ -1102 +1102 @@
           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) {
@@ -1118 +1120 @@
             /* set flag, that output has been stopped */
             tty->flow_ctrl |= FL_OSTOP;
+            tty->rawOutBufState = rob_busy;
             nToSend = 0;
           }
@@ -1131 +1134 @@
             /* 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->rawOutBufState = rob_busy;
             (*tty->device.write)(tty->minor, (char *)&tty->rawOutBuf[newTail], nToSend);
-            tty->rawOutBufState = rob_busy;
           }
           tty->rawOutBufTail = newTail;
@@ -1141 +1143 @@
         return nToSend;
 }
-
-