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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 1A1CDC433E1 for ; Wed, 22 Jul 2020 11:33:34 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E86BA20771 for ; Wed, 22 Jul 2020 11:33:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E86BA20771 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6D3D16E49D; Wed, 22 Jul 2020 11:33:33 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4821389B4D; Wed, 22 Jul 2020 11:33:32 +0000 (UTC) IronPort-SDR: 9YFp9nAOfyA6c6+x6pYp6kabMihn/c2aLJoYmQPcgG+se8JNDm1PQdZmuvt93VYlEtUanwaHU+ fJGNCHb/K0Qg== X-IronPort-AV: E=McAfee;i="6000,8403,9689"; a="147807473" X-IronPort-AV: E=Sophos;i="5.75,381,1589266800"; d="scan'208";a="147807473" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jul 2020 04:33:31 -0700 IronPort-SDR: crb0g6DXLg7BYUWf2B208Qvj2EicPyZp2PefbqKNCNUb8raK4+G1cXn5SWWRYqUz7yoxq86/gc 3vYsnm181upg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,381,1589266800"; d="scan'208";a="326667254" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by FMSMGA003.fm.intel.com with SMTP; 22 Jul 2020 04:33:28 -0700 Received: by stinkbox (sSMTP sendmail emulation); Wed, 22 Jul 2020 14:33:28 +0300 Date: Wed, 22 Jul 2020 14:33:28 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Andy Shevchenko Message-ID: <20200722113328.GA6112@intel.com> References: <20200529123317.20470-1-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200529123317.20470-1-andriy.shevchenko@linux.intel.com> X-Patchwork-Hint: comment User-Agent: Mutt/1.10.1 (2018-07-13) Subject: Re: [Intel-gfx] [PATCH v1] drm/i915/dsi: Drop double check for ACPI companion device X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Fri, May 29, 2020 at 03:33:17PM +0300, Andy Shevchenko wrote: > acpi_dev_get_resources() does perform the NULL pointer check against > ACPI companion device which is given as function parameter. Thus, > there is no need to duplicate this check in the caller. > = > Signed-off-by: Andy Shevchenko Sorry, I did look at this but apparently forgot to reply... > --- > drivers/gpu/drm/i915/display/intel_dsi_vbt.c | 24 ++++++++------------ > 1 file changed, 10 insertions(+), 14 deletions(-) > = > diff --git a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c b/drivers/gpu/d= rm/i915/display/intel_dsi_vbt.c > index 574dcfec9577..6f9e08cda964 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c > +++ b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c > @@ -426,23 +426,19 @@ static void i2c_acpi_find_adapter(struct intel_dsi = *intel_dsi, > { > struct drm_device *drm_dev =3D intel_dsi->base.base.dev; > struct device *dev =3D &drm_dev->pdev->dev; > - struct acpi_device *acpi_dev; > + struct acpi_device *acpi_dev =3D ACPI_COMPANION(dev); > struct list_head resource_list; > struct i2c_adapter_lookup lookup; > = > - acpi_dev =3D ACPI_COMPANION(dev); > - if (acpi_dev) { > - memset(&lookup, 0, sizeof(lookup)); > - lookup.slave_addr =3D slave_addr; > - lookup.intel_dsi =3D intel_dsi; > - lookup.dev_handle =3D acpi_device_handle(acpi_dev); > - > - INIT_LIST_HEAD(&resource_list); > - acpi_dev_get_resources(acpi_dev, &resource_list, > - i2c_adapter_lookup, > - &lookup); > - acpi_dev_free_resource_list(&resource_list); > - } > + memset(&lookup, 0, sizeof(lookup)); > + lookup.slave_addr =3D slave_addr; > + lookup.intel_dsi =3D intel_dsi; > + lookup.dev_handle =3D acpi_device_handle(acpi_dev); struct i2c_adapter_lookup lookup =3D { .slave_addr =3D ... }; ? > + > + INIT_LIST_HEAD(&resource_list); Declare as LIST_HEAD(resource_list); ? > + acpi_dev_get_resources(acpi_dev, &resource_list, > + i2c_adapter_lookup, &lookup); > + acpi_dev_free_resource_list(&resource_list); I was very confused by this code since on the first glance it appears to absolutely nothing. After a deeper look it looks like i2c_adapter_lookup() magically mutates intel_dsi->i2c_bus_num. Did I mention I hate functions with side effects? IMO would be much better if i2c_adapter_lookup() did what it says on the tin and just returned the adapter number and let the caller deal with it. But this is a pre-existing issue with the code and so not directly related to your patch. > } > #else > static inline void i2c_acpi_find_adapter(struct intel_dsi *intel_dsi, > -- = > 2.26.2 > = > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- = Ville Syrj=E4l=E4 Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx