From: Linus Walleij <linus.walleij@linaro.org>

The tx function of the DDC I2C slave emulation was returning 1
on all writes resulting in NACK in the I2C bus. Changing it to
0 makes the DDC I2C work fine with bit-banged I2C such as the
versatile I2C.

I guess it was not affecting whatever I2C controller this was
used with until now, but with the Versatile I2C it surely
does not work.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Message-id: 20180227104903.21353-4-linus.walleij@linaro.org
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/i2c/i2c-ddc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/i2c/i2c-ddc.c b/hw/i2c/i2c-ddc.c
index 199dac9e41..bec0c91e2d 100644
--- a/hw/i2c/i2c-ddc.c
+++ b/hw/i2c/i2c-ddc.c
@@ -259,12 +259,12 @@ static int i2c_ddc_tx(I2CSlave *i2c, uint8_t data)
         s->reg = data;
         s->firstbyte = false;
         DPRINTF("[EDID] Written new pointer: %u\n", data);
-        return 1;
+        return 0;
     }
 
     /* Ignore all writes */
     s->reg++;
-    return 1;
+    return 0;
 }
 
 static void i2c_ddc_init(Object *obj)
-- 
2.16.2