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From:   Giulio Benetti <giulio.benetti@micronovasrl.com>
To:     Maxime Ripard <maxime.ripard@bootlin.com>
Cc:     David Airlie <airlied@linux.ie>, Chen-Yu Tsai <wens@csie.org>,
        dri-devel@lists.freedesktop.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Giulio Benetti <giulio.benetti@micronovasrl.com>
Subject: [PATCH 1/2] drm/sun4i: tcon: fix check of tcon->panel null pointer
Date:   Tue,  2 Oct 2018 23:59:16 +0200
Message-Id: <20181002215917.1849-1-giulio.benetti@micronovasrl.com>
In-Reply-To: <20181001093612.GA13672@mwanda>
References: <20181001093612.GA13672@mwanda>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

At the moment, the check of tcon->panel to be valid is wrong. IS_ERR()
has been used, but that macro doesn't check if tcon->panel pointer is
null or not, but check if tcon->panel is between -1 and -4095(MAX_ERRNO).

Remove IS_ERR() from tcon->panel checking and let "if (tcon->panel)" as
condition to check if it's a pointer not null.

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
---
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index c78cd35a1294..e4b3bd0307ef 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -555,7 +555,7 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon,
 	 * Following code is a way to avoid quirks all around TCON
 	 * and DOTCLOCK drivers.
 	 */
-	if (!IS_ERR(tcon->panel)) {
+	if (tcon->panel) {
 		struct drm_panel *panel = tcon->panel;
 		struct drm_connector *connector = panel->connector;
 		struct drm_display_info display_info = connector->display_info;
-- 
2.17.1