PERFORCE change 101185 for review

[Warner Losh]

http://perforce.freebsd.org/chv.cgi?CH=101185

Change 101185 by imp at imp_lighthouse on 2006/07/10 07:57:06

	commentary update

Affected files ...

.. //depot/projects/arm/src/sys/arm/at91/uart_dev_at91usart.c#36 edit

Differences ...

==== //depot/projects/arm/src/sys/arm/at91/uart_dev_at91usart.c#36 (text+ko) ====

@@ -328,8 +328,10 @@
 	atsc = (struct at91_usart_softc *)sc;
 
 	/*
-	 * See if we have a TIMEOUT bit.  We disable all interrupts to
-	 * minimize interference.
+	 * See if we have a TIMEOUT bit.  We disable all interrupts as
+	 * a side effect.  Boot loaders may have enabled them.  Since
+	 * a TIMEOUT interrupt can't happen without other setup, the
+	 * apparent race here can't actually happen.
 	 */
 	WR4(&sc->sc_bas, USART_IDR, 0xffffffff);
 	WR4(&sc->sc_bas, USART_IER, USART_CSR_TIMEOUT);