From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sam Ravnborg Subject: Re: [PATCH] rpi_touchscreen_probe: check for failure case Date: Wed, 24 Jul 2019 07:17:00 +0200 Message-ID: <20190724051700.GA22730@ravnborg.org> References: <20190724025644.17163-1-navid.emamdoost@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190724025644.17163-1-navid.emamdoost@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Navid Emamdoost Cc: emamd001@umn.edu, kjlu@umn.edu, smccaman@umn.edu, Thierry Reding , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org List-Id: dri-devel@lists.freedesktop.org Hi Navid. Thanks for your patch. On Tue, Jul 23, 2019 at 09:56:43PM -0500, Navid Emamdoost wrote: > of_graph_get_next_endpoint may return NULL, so null check is needed. > > Signed-off-by: Navid Emamdoost The patch looks fine, but could you please audit the other calls in the probe function. For example of_graph_get_remote_port_parent() may also return NULL. If you do this then we can have the error handling reviewed in one go, and fixed in one patch. Sam > --- > drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c > index 28c0620dfe0f..2e0977e26fab 100644 > --- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c > +++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c > @@ -399,6 +399,8 @@ static int rpi_touchscreen_probe(struct i2c_client *i2c, > > /* Look up the DSI host. It needs to probe before we do. */ > endpoint = of_graph_get_next_endpoint(dev->of_node, NULL); > + if (!endpoint) > + return -ENODEV; > dsi_host_node = of_graph_get_remote_port_parent(endpoint); > host = of_find_mipi_dsi_host_by_node(dsi_host_node); > of_node_put(dsi_host_node); > -- > 2.17.1