[PATCH 07/13] drm/sun4i: hdmi: Don't leak sync polarity bits into packet control

Jernej Skrabec <[email protected]> Mon, 3 Aug 2026 18:10:45 +0200
Newsgroups dev.linux.lists.linux-sunxi,org.freedesktop.lists.dri-devel,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel
Message-ID <51ba0918ce016a4b45313d5df1b6ce31b8c8731e.1785772659.git.jernej.skrabec@gmail.com>
sun4i_hdmi_enable() keeps using the same variable after it programmed
the video timing polarity register with it. The leftover TX_CLK, HSYNC
and VSYNC bits are then ORed into the packet control register, where
each nibble selects the packet type sent in one slot.

As a result, slot 0 selects packet type 3 instead of the AVI infoframe
whenever the mode has positive HSYNC polarity, and the TX_CLK bits set
nibbles which the driver never programs.

Assign the packet types instead of ORing them into the stale value.

Fixes: 9ca6bc246035 ("drm/sun4i: hdmi: Move mode_set into enable")
Signed-off-by: Jernej Skrabec <[email protected]>
---
 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
index 74c7c3720ba8..a27d394d0570 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
@@ -161,7 +161,7 @@ static void sun4i_hdmi_enable(struct drm_encoder *encoder,
 
 	drm_atomic_helper_connector_hdmi_update_infoframes(connector, state);
 
-	val |= SUN4I_HDMI_PKT_CTRL_TYPE(0, SUN4I_HDMI_PKT_AVI);
+	val = SUN4I_HDMI_PKT_CTRL_TYPE(0, SUN4I_HDMI_PKT_AVI);
 	val |= SUN4I_HDMI_PKT_CTRL_TYPE(1, SUN4I_HDMI_PKT_END);
 	writel(val, hdmi->base + SUN4I_HDMI_PKT_CTRL_REG(0));
 
-- 
2.43.0