drm/sun4i: tcon: prevent tcon->panel dereference if NULL

If tcon->panel pointer is NULL, trying to dereference from it
(i.e. tcon->panel->connector) will cause a null pointer dereference.

Add tcon->panel null pointer check before calling
sun4i_tcon0_mode_set_dithering().

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Fixes: f11adcecbd ("drm/sun4i: tcon: Add dithering support for
                      RGB565/RGB666 LCD panels")
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181005215951.99003-2-giulio.benetti@micronovasrl.com
This commit is contained in:
Giulio Benetti 2018-10-05 23:59:51 +02:00 committed by Maxime Ripard
parent 7f4cedd882
commit a8939766c7
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@ -491,7 +491,8 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon,
sun4i_tcon0_mode_set_common(tcon, mode);
/* Set dithering if needed */
sun4i_tcon0_mode_set_dithering(tcon, tcon->panel->connector);
if (tcon->panel)
sun4i_tcon0_mode_set_dithering(tcon, tcon->panel->connector);
/* Adjust clock delay */
clk_delay = sun4i_tcon_get_clk_delay(mode, 0);