[for-1.4,v4,3/6] tmp105: Fix I2C protocol bug

Submitted by Andreas Färber on Jan. 16, 2013, 12:57 a.m.

Details

Message ID 1358297879-26576-4-git-send-email-andreas.faerber@web.de
State New
Headers show

Commit Message

Andreas Färber Jan. 16, 2013, 12:57 a.m.
An early length postincrement in the TMP105's I2C TX path led to
transfers of more than one byte to place the second byte in the third
byte's place within the buffer and the third byte to get discarded.

Fix this by explictly incrementing the length after the checks but
before the callback is called, which again checks the length.

Adjust the Coding Style while at it.

Signed-off-by: Alex Horn <alex.horn@cs.ox.ac.uk>
Signed-off-by: Andreas Färber <andreas.faerber@web.de>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
---
 hw/tmp105.c |    9 ++++++---
 1 Datei geändert, 6 Zeilen hinzugefügt(+), 3 Zeilen entfernt(-)

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diff --git a/hw/tmp105.c b/hw/tmp105.c
index 0ade4eb..10d94c9 100644
--- a/hw/tmp105.c
+++ b/hw/tmp105.c
@@ -153,11 +153,14 @@  static int tmp105_tx(I2CSlave *i2c, uint8_t data)
 {
     TMP105State *s = (TMP105State *) i2c;
 
-    if (!s->len ++)
+    if (s->len == 0) {
         s->pointer = data;
-    else {
-        if (s->len <= 2)
+        s->len++;
+    } else {
+        if (s->len <= 2) {
             s->buf[s->len - 1] = data;
+        }
+        s->len++;
         tmp105_write(s);
     }