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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22C6EC433F5 for ; Thu, 4 Nov 2021 19:54:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A0B561213 for ; Thu, 4 Nov 2021 19:54:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231982AbhKDT5W (ORCPT ); Thu, 4 Nov 2021 15:57:22 -0400 Received: from mga02.intel.com ([134.134.136.20]:36856 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231572AbhKDT5V (ORCPT ); Thu, 4 Nov 2021 15:57:21 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10158"; a="218980327" X-IronPort-AV: E=Sophos;i="5.87,209,1631602800"; d="scan'208";a="218980327" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Nov 2021 12:54:42 -0700 X-IronPort-AV: E=Sophos;i="5.87,209,1631602800"; d="scan'208";a="501674768" Received: from mihaelac-mobl.ger.corp.intel.com (HELO localhost) ([10.249.32.21]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Nov 2021 12:54:34 -0700 From: Jani Nikula To: Sam Ravnborg , Javier Martinez Canillas Cc: David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, Gurchetan Singh , Gerd Hoffmann , amd-gfx@lists.freedesktop.org, VMware Graphics , Ben Skeggs , nouveau@lists.freedesktop.org, Dave Airlie , intel-gfx@lists.freedesktop.org, Peter Robinson , Michel =?utf-8?Q?D=C3=A4nzer?= , Hans de Goede , Rodrigo Vivi , virtualization@lists.linux-foundation.org, Pekka Paalanen , "Pan\, Xinhui" , linux-kernel@vger.kernel.org, spice-devel@lists.freedesktop.org, Thomas Zimmermann , Alex Deucher , Christian =?utf-8?Q?K=C3=B6nig?= Subject: Re: [PATCH v2 1/2] drm: Add a drm_drv_enabled() to check if drivers should be enabled In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20211104160707.1407052-1-javierm@redhat.com> <20211104160707.1407052-2-javierm@redhat.com> <87r1bvajna.fsf@intel.com> Date: Thu, 04 Nov 2021 21:54:32 +0200 Message-ID: <87lf23ae87.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 04 Nov 2021, Sam Ravnborg wrote: > Hi Javier, > >> >> >>> >> >>> - if (vgacon_text_force() && i915_modparams.modeset == -1) >> >>> + ret = drm_drv_enabled(&driver); >> >> >> >> You pass the local driver variable here - which looks wrong as this is >> >> not the same as the driver variable declared in another file. >> > >> >> Yes, Jani mentioned it already. I got confused and thought that the driver >> variable was also defined in the same compilation unit... >> >> Maybe I could squash the following change? >> >> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c >> index b18a250e5d2e..b8f399b76363 100644 >> --- a/drivers/gpu/drm/i915/i915_drv.c >> +++ b/drivers/gpu/drm/i915/i915_drv.c >> @@ -89,7 +89,7 @@ >> #include "intel_region_ttm.h" >> #include "vlv_suspend.h" >> >> -static const struct drm_driver driver; >> +const struct drm_driver driver; > No, variables with such a generic name will clash. > > Just add a > const drm_driver * i915_drm_driver(void) > { > return &driver; > } > > And then use this function to access the drm_driver variable. Agreed on the general principle of exposing interfaces over data. But... why? I'm still at a loss what problem this solves. We pass &driver to exactly one place, devm_drm_dev_alloc(), and it's neatly hidden away. BR, Jani. -- Jani Nikula, Intel Open Source Graphics Center