From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B99DC10F03 for ; Thu, 25 Apr 2019 09:20:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 085DC214C6 for ; Thu, 25 Apr 2019 09:20:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="irIL/oCS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727726AbfDYJUq (ORCPT ); Thu, 25 Apr 2019 05:20:46 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:35156 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726302AbfDYJUq (ORCPT ); Thu, 25 Apr 2019 05:20:46 -0400 Received: from pendragon.ideasonboard.com (net-37-182-44-227.cust.vodafonedsl.it [37.182.44.227]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 0D34A5F; Thu, 25 Apr 2019 11:20:44 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1556184044; bh=wKFgUNVPvgrqDMksLeW8+jhcvEQFGoAKVyqd+Lj7fmA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=irIL/oCS3OmdEXTEPeCYUpdW7MpBKSIAi3bxudpC1daOyrlL5MZHjB8g07jprkRBh XoQtV74cPXqktR09x9LFeRGpymtzgY2c9NXJz8o09HLOs8k0XTee3LWkPvRepxGd2J UqDHlfaJWtIozRRE6JO6AkRwmfg9XtBm75s710w0= Date: Thu, 25 Apr 2019 12:20:33 +0300 From: Laurent Pinchart 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 Subject: Re: [PATCH] drm/bridge/synopsys: dsi: Don't blindly call post_disable 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 Content-Disposition: inline In-Reply-To: <20190424142148.25927-1-matt.redfearn@thinci.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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