From: Thomas Andrews <tandrews@grok.co.za>
Date: Sat, 1 Jul 2006 15:05:12 +0000 (+0200)
Subject: [PATCH] scx200_acb: Fix the state machine
X-Git-Tag: v2.6.18-rc2~94^2~10
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fd627a01477dadaef3bc8556e5e9d0ef80310c3a;p=linux-2.6

[PATCH] scx200_acb: Fix the state machine

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@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/i2c/busses/scx200_acb.c b/drivers/i2c/busses/scx200_acb.c
index 22a3eda041..454086affa 100644
--- a/drivers/i2c/busses/scx200_acb.c
+++ b/drivers/i2c/busses/scx200_acb.c
@@ -184,21 +184,21 @@ static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
 		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: