[i2c] [PATCH 03/13] scx200_acb: Fix the state machine

Jean Delvare khali at linux-fr.org
Sat Jul 1 17:05:12 CEST 2006


From: Thomas Andrews <tandrews at grok.co.za>

Fix the scx200_acb state machine:

* Nack was sent one byte too late on reads >= 2 bytes.
* Stop bit was set one byte too late on reads.

Signed-off-by: Jean Delvare <khali at linux-fr.org>
---
 drivers/i2c/busses/scx200_acb.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- linux-2.6.17-git.orig/drivers/i2c/busses/scx200_acb.c	2006-06-21 09:38:18.000000000 +0200
+++ linux-2.6.17-git/drivers/i2c/busses/scx200_acb.c	2006-06-21 20:48:46.000000000 +0200
@@ -184,21 +184,21 @@
 		break;
 
 	case state_read:
-		/* Set ACK if receiving the last byte */
-		if (iface->len == 1)
+		/* Set ACK if _next_ byte will be the last one */
+		if (iface->len == 2)
 			outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
 		else
 			outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
 
-		*iface->ptr++ = inb(ACBSDA);
-		--iface->len;
-
-		if (iface->len == 0) {
+		if (iface->len == 1) {
 			iface->result = 0;
 			iface->state = state_idle;
 			outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
 		}
 
+		*iface->ptr++ = inb(ACBSDA);
+		--iface->len;
+
 		break;
 
 	case state_write:

-- 
Jean Delvare



More information about the i2c mailing list