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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 70CD6C433EF for ; Thu, 24 Feb 2022 17:55:31 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F23F310ECA1; Thu, 24 Feb 2022 17:55:30 +0000 (UTC) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8986810EC98 for ; Thu, 24 Feb 2022 17:55:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1645725329; x=1677261329; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=yOv6D77pW2BxSP4GZ68RS0MyWyTzTM7PjPAbGmEeKHk=; b=F1ugkjk7GLTLMHrzNpIhNPyhwY/V+CB+ZCJuBpkU20zufMvJsazE1449 7jhXewldA4oRlAIV4/eiHjGQrsJVPbkDXKdvwhdYl75sRJpTXsmUHEFfd z5FSge9H0UruZFcUvGXOUoy+ywA4uIIvWQmjyDrCAn/60A9lRS/uLdwuv BB2wySu977rYtiBQHnp0tfxBr3Za9qP2ysuClVVUGMo8gt8tdIHDF2Jiy h/jFz2AQn4syRSOKcft7RCqGPV6fIKfVWObQX4FyLKCPoa4q/v0Ka32ck RIu9dZOYIr4RpnL+eTsDLIwh0TLiNB2EXmjO7HMIAsgB6vrAFhxulVD9n Q==; X-IronPort-AV: E=McAfee;i="6200,9189,10268"; a="252498402" X-IronPort-AV: E=Sophos;i="5.90,134,1643702400"; d="scan'208";a="252498402" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Feb 2022 09:55:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,134,1643702400"; d="scan'208";a="543786217" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.151]) by fmsmga007.fm.intel.com with SMTP; 24 Feb 2022 09:55:26 -0800 Received: by stinkbox (sSMTP sendmail emulation); Thu, 24 Feb 2022 19:55:25 +0200 Date: Thu, 24 Feb 2022 19:55:25 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: "Souza, Jose" Message-ID: References: <20220223205551.813749-1-jose.souza@intel.com> <9d5049fe87faf41fba7649335cecbd64fba0c77a.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9d5049fe87faf41fba7649335cecbd64fba0c77a.camel@intel.com> X-Patchwork-Hint: comment Subject: Re: [Intel-gfx] [PATCH v2] drm/i915/display: Use unions per platform in intel_dpll_hw_state 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" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, Feb 24, 2022 at 05:48:10PM +0000, Souza, Jose wrote: > On Thu, 2022-02-24 at 17:39 +0200, Ville Syrjälä wrote: > > On Thu, Feb 24, 2022 at 01:49:36PM +0000, Souza, Jose wrote: > > > On Thu, 2022-02-24 at 15:25 +0200, Ville Syrjälä wrote: > > > > On Thu, Feb 24, 2022 at 01:17:35PM +0000, Souza, Jose wrote: > > > > > On Thu, 2022-02-24 at 12:20 +0200, Ville Syrjälä wrote: > > > > > > On Wed, Feb 23, 2022 at 12:55:51PM -0800, José Roberto de Souza wrote: > > > > > > > > > > > > > + union { > > > > > > > + /* icl+ TC */ > > > > > > > + struct { > > > > > > > + u32 mg_refclkin_ctl; > > > > > > > + u32 mg_clktop2_coreclkctl1; > > > > > > > + u32 mg_clktop2_hsclkctl; > > > > > > > + u32 mg_pll_div0; > > > > > > > + u32 mg_pll_div1; > > > > > > > + u32 mg_pll_lf; > > > > > > > + u32 mg_pll_frac_lock; > > > > > > > + u32 mg_pll_ssc; > > > > > > > + u32 mg_pll_bias; > > > > > > > + u32 mg_pll_tdc_coldst_bias; > > > > > > > + u32 mg_pll_bias_mask; > > > > > > > + u32 mg_pll_tdc_coldst_bias_mask; > > > > > > > + }; > > > > > > > + > > > > > > > + /* bxt */ > > > > > > > + struct { > > > > > > > + /* bxt */ > > > > > > > + u32 ebb0; > > > > > > > + u32 ebb4; > > > > > > > + u32 pll0; > > > > > > > + u32 pll1; > > > > > > > + u32 pll2; > > > > > > > + u32 pll3; > > > > > > > + u32 pll6; > > > > > > > + u32 pll8; > > > > > > > + u32 pll9; > > > > > > > + u32 pll10; > > > > > > > + u32 pcsdw12; > > > > > > > + }; > > > > > > > > > > > > Wasn't there some funny compiler bug around anonymous unions? > > > > > > git log --grep='anon.*union' seems to agree. Please double check > > > > > > that stuff to make sure this is actually safe. > > > > > > > > > > I don't see any patch referring to compiler issues with 'git log --grep='anon.*union', what I see is other subsystems making use of it too. > > > > > Can you share the commit hash that you are referring to? > > > > > > > > $ git log --format=oneline --grep='anon.*union' -- drivers/gpu/drm/i915 > > > > > > > > > > I see issues with initialization of anonymous union but we don't initialize intel_dpll_hw_state. > > > Also it was fixed on GCC 4.6 that is older than current GCC requirement to build kernel(GCC 5.1). > > > > > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10676 > > > > OK. However, after pondering this a bit I think naming things wpild > > probably be better here. You have a bunch of if ladders now where each > > branch only operates on one of the structs inside the union. IMO the > > anonymity is making it rather hard to see if the code is even correct. > > Just to mare sure we are in the same page, you want to have this? > > > struct icl_tc { > u32 mg_refclkin_ctl; > u32 mg_clktop2_coreclkctl1; > u32 mg_clktop2_hsclkctl; > u32 mg_pll_div0; > u32 mg_pll_div1; > u32 mg_pll_lf; > u32 mg_pll_frac_lock; > u32 mg_pll_ssc; > u32 mg_pll_bias; > u32 mg_pll_tdc_coldst_bias; > u32 mg_pll_bias_mask; > u32 mg_pll_tdc_coldst_bias_mask; > }; struct { .... } whatever; In this case the name that immediately came to mind was just "mg" (+ then drop the extra mg_ namespace in the members). We could name the types too I guess if we wanted to use those somewhere. Eg. instead of passing in the whole union to some function we could just pass in the specific substruct. > > So we would need to access members with icl_tc.mg_refclkin_ctl? > > I can do that but the diff will be huge. > Are you okay with that too Imre? > > > > > -- Ville Syrjälä Intel