drm/panel: otm8009a: Add delay at the end of initialization

[ Upstream commit 0084c3c71126fc878c6dab8a6ab8ecc484c2be02 ]

At the end of initialization, a delay is required by the panel. Without
this delay, the panel could received a frame early & generate a crash of
panel (black screen).

Signed-off-by: Yannick Fertré <yannick.fertre@st.com>
Reviewed-by: Philippe Cornu <philippe.cornu@st.com>
Tested-by: Philippe Cornu <philippe.cornu@st.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1553155445-13407-1-git-send-email-yannick.fertre@st.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/gpu/drm/panel/panel-orisetech-otm8009a.c

@@ -248,6 +248,9 @@ static int otm8009a_init_sequence(struct otm8009a *ctx)
 	/* Send Command GRAM memory write (no parameters) */
 	dcs_write_seq(ctx, MIPI_DCS_WRITE_MEMORY_START);
 
+	/* Wait a short while to let the panel be ready before the 1st frame */
+	mdelay(10);
+
 	return 0;
 }