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Fix CTS handling in pmac-zilog.c

PATCH New Benjamin Herrenschmidt 1 participant 1 message May 8, 2004 PowerPC

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PATCH 1/1 Fix CTS handling in pmac-zilog.c

(From: Paul Mackerras <[email protected]>)

This patch fixes a bug in the pmac-zilog driver where if you enable CRTSCTS mode, it won't output data when CTS is asserted. On powermacs, the CTS input is inverted. It also fixes a logic bug in testing for CTS and DCD changes.

drivers/serial/pmac_zilog.c +5 -4
diff -urN linux-2.5/drivers/serial/pmac_zilog.c pmac-2.5/drivers/serial/pmac_zilog.c
@@ -352,13 +352,14 @@
 		/* The Zilog just gives us an interrupt when DCD/CTS/etc. change.
 		 * But it does not tell us which bit has changed, we have to keep
 		 * track of this ourselves.
+		 * The CTS input is inverted for some reason.  -- paulus
 		 */
-		if ((status & DCD) ^ uap->prev_status)
+		if ((status ^ uap->prev_status) & DCD)
 			uart_handle_dcd_change(&uap->port,
 					       (status & DCD));
-		if ((status & CTS) ^ uap->prev_status)
+		if ((status ^ uap->prev_status) & CTS)
 			uart_handle_cts_change(&uap->port,
-					       (status & CTS));
+					       !(status & CTS));
 
 		wake_up_interruptible(&uap->port.info->delta_msr_wait);
 	}
@@ -595,7 +596,7 @@
 		ret |= TIOCM_CAR;
 	if (status & SYNC_HUNT)
 		ret |= TIOCM_DSR;
-	if (status & CTS)
+	if (!(status & CTS))
 		ret |= TIOCM_CTS;
 
 	return ret;
Signature · 1 line
Benjamin Herrenschmidt <[email protected]>