PERFORCE change 136821 for review

[Randall R. Stewart]

http://perforce.freebsd.org/chv.cgi?CH=136821

Change 136821 by rrs at rrs-mips2-jnpr on 2008/03/04 15:05:40

	Ok, other weirdness of the oct16550 figured out. We will occasionaly,
	when getting a BREAK, get the proper indication from the IIR 
	register, but the LSR tells us there is only a character. Which is
	       the strange '0' character that accompanies each break. So transmute
	       this to a break. We can always now get into the debugger with
	       this fix :-)

Affected files ...

.. //depot/projects/mips2-jnpr/src/sys/mips/mips32/octeon32/uart_dev_oct16550.c#17 edit

Differences ...

==== //depot/projects/mips2-jnpr/src/sys/mips/mips32/octeon32/uart_dev_oct16550.c#17 (text+ko) ====

@@ -87,6 +87,9 @@
 #define uart_getreg(bas, reg)	\
 	bus_space_read_8((bas)->bst, (bas)->bsh, uart_regofs(bas, reg))
 
+int rrs_uart_debug=0;
+int rrs_uart_show_tmit_too=0;
+
 /*
  * Clear pending interrupts. THRE is cleared by reading IIR. Data
  * that may have been received gets lost here.
@@ -632,6 +635,7 @@
 	iir = iir2 & IIR_IMASK;
 	if (iir != IIR_NOPEND) {
 	          if (iir == IIR_RLS) {
+			unsigned int xc;
 			lsr = uart_getreg(bas, OCT_REG_LSR);
 			if (lsr & LSR_OE)
 				ipend |= SER_INT_OVERRUN;
@@ -647,7 +651,6 @@
 				   * thats a bug). But regardless we don't
 				   * want to push in a subsequent 0.
 				   */
-				  unsigned int xc;
 				  xc = uart_getreg(bas, OCT_REG_RBR);
 				  if (xc != 0) {
 				    /* TSNH */
@@ -657,9 +660,25 @@
 				  lsr = uart_getreg(bas, OCT_REG_LSR);
 				}
 			}
-			if (lsr & LSR_RXRDY)
-			  ipend |= SER_INT_RXREADY;
-			
+			if (lsr & LSR_RXRDY) {
+				  /* This is utterly wierd. If we get
+				   * a  IIR_RLS, we should ONT just
+				   * read a LSR_RXRDY. So we will re-read the
+				   * register and the character. If the
+				   * char is 0, then its the 0 that accompanies
+				   * the BREAK and the hardware just futzed.
+				   * If its other than that, we loose and drop
+				   * the character.
+				   */
+			          xc = uart_getreg(bas, OCT_REG_RBR);
+				  lsr = uart_getreg(bas, OCT_REG_LSR);
+				  if (xc == 0) {
+				    ipend |= SER_INT_BREAK;
+				  } else {
+				    /* TSNH, but neither should this whole block */
+				    printf("We loose a char %x\n", xc);
+				  }
+			}
 		} else if (iir == IIR_RXRDY) {
 			ipend |= SER_INT_RXREADY;
 
@@ -684,6 +703,8 @@
 			niir = uart_getreg(bas, OCT_REG_IIR);
 			lsr = uart_getreg(bas, OCT_REG_LSR);
 			usr = uart_getreg(bas, OCT_REG_USR);
+			printf("Got IIR_BUSY:%x niir:%x lsr:%x usr:%x\n",
+			       iir2, niir, lsr, usr);
 		}
 	}
 	uart_unlock(sc->sc_hwmtx);