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

On Tue, Aug 4, 2026 at 12:11=E2=80=AFAM Jernej Skrabec <jernej.skrabec@gmai=
l.com> wrote:
>
> 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]>

Acked-by: Chen-Yu Tsai <[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/sun=
4i/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 *enc=
oder,
>
>         drm_atomic_helper_connector_hdmi_update_infoframes(connector, sta=
te);
>
> -       val |=3D SUN4I_HDMI_PKT_CTRL_TYPE(0, SUN4I_HDMI_PKT_AVI);
> +       val =3D SUN4I_HDMI_PKT_CTRL_TYPE(0, SUN4I_HDMI_PKT_AVI);
>         val |=3D SUN4I_HDMI_PKT_CTRL_TYPE(1, SUN4I_HDMI_PKT_END);
>         writel(val, hdmi->base + SUN4I_HDMI_PKT_CTRL_REG(0));
>
> --
> 2.43.0
>
>