[PATCH v2] drm/i2c: tda998x: Fix bad checksum of the HDMI AVI infoframe

[Jean-Francois Moine]

Using hdmi_avi_infoframe_pack() to create the AVI infoframe calculates
the checksum of the frame and breaks the second calculation which is
done in tda998x_write_if(). Then the HDMI AVI frame is wrong and
the display device does not handle correctly the video frames.

Fixes: 8c7a075da9f7980c ("use drm_hdmi_avi_infoframe_from_display_mode()")
Signed-off-by: Jean-Francois Moine <moinejf at free.fr>
---
v2: add the Fixes: tag
---
 drivers/gpu/drm/i2c/tda998x_drv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c
index fe1599d..424228b 100644
--- a/drivers/gpu/drm/i2c/tda998x_drv.c
+++ b/drivers/gpu/drm/i2c/tda998x_drv.c
@@ -606,8 +606,6 @@ static void
 tda998x_write_if(struct tda998x_priv *priv, uint8_t bit, uint16_t addr,
 		 uint8_t *buf, size_t size)
 {
-	buf[PB(0)] = tda998x_cksum(buf, size);
-
 	reg_clear(priv, REG_DIP_IF_FLAGS, bit);
 	reg_write_range(priv, addr, buf, size);
 	reg_set(priv, REG_DIP_IF_FLAGS, bit);
@@ -627,6 +625,8 @@ tda998x_write_aif(struct tda998x_priv *priv, struct tda998x_encoder_params *p)
 	buf[PB(4)] = p->audio_frame[4];
 	buf[PB(5)] = p->audio_frame[5] & 0xf8; /* DM_INH + LSV */
 
+	buf[PB(0)] = tda998x_cksum(buf, sizeof(buf));
+
 	tda998x_write_if(priv, DIP_IF_FLAGS_IF4, REG_IF4_HB0, buf,
 			 sizeof(buf));
 }
-- 
2.4.6