Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753120AbdGMT67 (ORCPT ); Thu, 13 Jul 2017 15:58:59 -0400 Received: from mail-yb0-f195.google.com ([209.85.213.195]:36576 "EHLO mail-yb0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752745AbdGMT65 (ORCPT ); Thu, 13 Jul 2017 15:58:57 -0400 MIME-Version: 1.0 In-Reply-To: <20170713174232.GK12629@intel.com> References: <20170420215605.176722-1-mka@chromium.org> <20170505172636.GA128305@google.com> <20170505174043.GK12629@intel.com> <20170713101351.GS12629@intel.com> <20170713174232.GK12629@intel.com> From: =?UTF-8?Q?St=C3=A9phane_Marchesin?= Date: Thu, 13 Jul 2017 12:58:16 -0700 Message-ID: Subject: Re: [Intel-gfx] [PATCH RESEND] drm/i915: Fix pipe/transcoder enum mismatches To: =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= Cc: =?UTF-8?Q?St=C3=A9phane_Marchesin?= , intel-gfx , Linux Kernel Mailing List , "dri-devel@lists.freedesktop.org" , Michael Davidson , Grant Grundler , Matthias Kaehlcke , Daniel Vetter Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v6DJx4ef015623 Content-Length: 3212 Lines: 75 On Thu, Jul 13, 2017 at 10:42 AM, Ville Syrjälä wrote: > On Thu, Jul 13, 2017 at 09:23:11AM -0700, Stéphane Marchesin wrote: >> On Thu, Jul 13, 2017 at 3:13 AM, Ville Syrjälä >> wrote: >> > On Wed, Jul 12, 2017 at 07:28:14PM -0700, Stéphane Marchesin wrote: >> >> On Fri, May 5, 2017 at 10:40 AM, Ville Syrjälä >> >> wrote: >> >> > >> >> > On Fri, May 05, 2017 at 10:26:36AM -0700, Matthias Kaehlcke wrote: >> >> > > El Thu, Apr 20, 2017 at 02:56:05PM -0700 Matthias Kaehlcke ha dit: >> >> > > >> >> > > > In several instances the driver passes an 'enum pipe' value to a >> >> > > > function expecting an 'enum transcoder' and viceversa. Since PIPE_x and >> >> > > > TRANSCODER_x have the same values this doesn't cause functional >> >> > > > problems. Still it is incorrect and causes clang to generate warnings >> >> > > > like this: >> >> > > > >> >> > > > drivers/gpu/drm/i915/intel_display.c:1844:34: warning: implicit >> >> > > > conversion from enumeration type 'enum transcoder' to different >> >> > > > enumeration type 'enum pipe' [-Wenum-conversion] >> >> > > > assert_fdi_rx_enabled(dev_priv, TRANSCODER_A); >> >> > > > >> >> > > > Change the code to pass values of the type expected by the callee. >> >> > > > >> >> > > > Signed-off-by: Matthias Kaehlcke >> >> > > > --- >> >> > > > drivers/gpu/drm/i915/intel_display.c | 4 ++-- >> >> > > > drivers/gpu/drm/i915/intel_dp.c | 6 ++++-- >> >> > > > drivers/gpu/drm/i915/intel_hdmi.c | 6 ++++-- >> >> > > > drivers/gpu/drm/i915/intel_sdvo.c | 6 ++++-- >> >> > > > 4 files changed, 14 insertions(+), 8 deletions(-) >> >> > > >> >> > > Ping, any comments on this patch? >> >> > >> >> > I'm not convinced the patch is making things any better really. To >> >> > fix this really properly, I think we'd need to introduce a new enum >> >> > pch_transcoder and thus avoid the confusion of which type of >> >> > transcoder we're talking about. Currently most places expect an >> >> > enum pipe when dealing with PCH transcoders, and enum transcoder >> >> > when dealing with CPU transcoders. But there are some exceptions >> >> > of course. >> >> >> >> >> >> I don't follow -- these functions take an enum transcoder; what's >> >> wrong about passing what they expect? It seems like what you are >> >> asking for has nothing to do with the warning here... >> > >> > There's a warning? I don't get any. >> >> Yup, clang generates a warning. >> >> > >> > Anyways, I just don't see much point in blindly changing the types >> > because it doesn't actually solve the underlying confusion for human >> > readers. It might even make it worse, not sure. >> >> The function expects type A, you pass type B, how can that ever be the >> right thing to do? > > Because maybe the function should be taking in type B instead. So, if you think this is wrong, can you fix this warning in a way that you'd like? Stéphane > > -- > Ville Syrjälä > Intel OTC > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel