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 DA2CEC433EF for ; Mon, 18 Oct 2021 09:10:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4D5E6101B for ; Mon, 18 Oct 2021 09:10:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231382AbhJRJND (ORCPT ); Mon, 18 Oct 2021 05:13:03 -0400 Received: from mga09.intel.com ([134.134.136.24]:32397 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231149AbhJRJNA (ORCPT ); Mon, 18 Oct 2021 05:13:00 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10140"; a="228087115" X-IronPort-AV: E=Sophos;i="5.85,381,1624345200"; d="scan'208";a="228087115" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Oct 2021 02:10:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.85,381,1624345200"; d="scan'208";a="443330095" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.171]) by orsmga006.jf.intel.com with SMTP; 18 Oct 2021 02:10:41 -0700 Received: by stinkbox (sSMTP sendmail emulation); Mon, 18 Oct 2021 12:10:40 +0300 Date: Mon, 18 Oct 2021 12:10:40 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Nick Desaulniers Cc: Nathan Chancellor , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, =?iso-8859-1?Q?D=E1vid_Bolvansk=FD?= Subject: Re: [PATCH] drm/i915: Avoid bitwise vs logical OR warning in snb_wm_latency_quirk() Message-ID: References: <20211014211916.3550122-1-nathan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Patchwork-Hint: comment Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 14, 2021 at 02:21:43PM -0700, Nick Desaulniers wrote: > On Thu, Oct 14, 2021 at 2:19 PM Nathan Chancellor wrote: > > > > A new warning in clang points out a place in this file where a bitwise > > OR is being used with boolean types: > > > > drivers/gpu/drm/i915/intel_pm.c:3066:12: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical] > > changed = ilk_increase_wm_latency(dev_priv, dev_priv->wm.pri_latency, 12) | > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > This construct is intentional, as it allows every one of the calls to > > ilk_increase_wm_latency() to occur (instead of short circuiting with > > logical OR) while still caring about the result of each call. > > > > To make this clearer to the compiler, use the '|=' operator to assign > > the result of each ilk_increase_wm_latency() call to changed, which > > keeps the meaning of the code the same but makes it obvious that every > > one of these calls is expected to happen. Sure, why not. > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1473 > > Reported-by: Nick Desaulniers > > Thanks for the patch! > Suggested-by: Dávid Bolvanský > Reviewed-by: Nick Desaulniers > Thanks for the patch+review. Applied to drm-intel-next. > > Signed-off-by: Nathan Chancellor > > --- > > drivers/gpu/drm/i915/intel_pm.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > > index f90fe39cf8ca..aaa3a0998e4c 100644 > > --- a/drivers/gpu/drm/i915/intel_pm.c > > +++ b/drivers/gpu/drm/i915/intel_pm.c > > @@ -3050,9 +3050,9 @@ static void snb_wm_latency_quirk(struct drm_i915_private *dev_priv) > > * The BIOS provided WM memory latency values are often > > * inadequate for high resolution displays. Adjust them. > > */ > > - changed = ilk_increase_wm_latency(dev_priv, dev_priv->wm.pri_latency, 12) | > > - ilk_increase_wm_latency(dev_priv, dev_priv->wm.spr_latency, 12) | > > - ilk_increase_wm_latency(dev_priv, dev_priv->wm.cur_latency, 12); > > + changed = ilk_increase_wm_latency(dev_priv, dev_priv->wm.pri_latency, 12); > > + changed |= ilk_increase_wm_latency(dev_priv, dev_priv->wm.spr_latency, 12); > > + changed |= ilk_increase_wm_latency(dev_priv, dev_priv->wm.cur_latency, 12); > > > > if (!changed) > > return; > > > > base-commit: d73b17465d6da0a94bc0fcc86b150e1e923e8f71 > > -- > > 2.33.1.637.gf443b226ca > > > > > -- > Thanks, > ~Nick Desaulniers -- Ville Syrjälä Intel