From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH] drm/bridge/synopsys: dsi: Don't blindly call post_disable Date: Thu, 25 Apr 2019 12:20:33 +0300 Message-ID: <20190425092033.GB4557@pendragon.ideasonboard.com> References: <20190424142148.25927-1-matt.redfearn@thinci.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20190424142148.25927-1-matt.redfearn@thinci.com> Sender: linux-kernel-owner@vger.kernel.org To: Matt Redfearn Cc: Andrzej Hajda , Philippe Cornu , "dri-devel@lists.freedesktop.org" , Matthew Redfearn , Nickey Yang , Heiko Stuebner , Archit Taneja , "linux-kernel@vger.kernel.org" , David Airlie , Daniel Vetter List-Id: dri-devel@lists.freedesktop.org Hi Matt, Thank you for the patch. On Wed, Apr 24, 2019 at 02:22:00PM +0000, Matt Redfearn wrote: > The DRM documentation states that post_disable is an optional callback. > As such an implementing device may not populate it. To avoid panicing > the kernel by calling a NULL function pointer, we should NULL check it > before blindy calling it. > > Signed-off-by: Matt Redfearn Reviewed-by: Laurent Pinchart > --- > > drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c > index 38e88071363..0ee440216b8 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c > @@ -805,7 +805,8 @@ static void dw_mipi_dsi_bridge_post_disable(struct drm_bridge *bridge) > * This needs to be fixed in the drm_bridge framework and the API > * needs to be updated to manage our own call chains... > */ > - dsi->panel_bridge->funcs->post_disable(dsi->panel_bridge); > + if (dsi->panel_bridge->funcs->post_disable) > + dsi->panel_bridge->funcs->post_disable(dsi->panel_bridge); > > if (dsi->slave) { > dw_mipi_dsi_disable(dsi->slave); -- Regards, Laurent Pinchart