From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [PATCH] drm: atomic helper: fix W=1 warnings Date: Fri, 4 Oct 2019 15:27:47 +0300 Message-ID: <20191004122747.GT1208@intel.com> References: <20190909135205.10277-1-benjamin.gaignard@st.com> <20190909135205.10277-2-benjamin.gaignard@st.com> <20191003142738.GM1208@intel.com> <20191003150526.GN1208@intel.com> <20191003154627.GQ1208@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Benjamin Gaignard Cc: Benjamin Gaignard , David Airlie , Daniel Vetter , Linux Kernel Mailing List , ML dri-devel List-Id: dri-devel@lists.freedesktop.org On Fri, Oct 04, 2019 at 12:48:02PM +0200, Benjamin Gaignard wrote: > Le jeu. 3 oct. 2019 ā 17:46, Ville Syrjälä > a écrit : > > > > On Thu, Oct 03, 2019 at 05:37:15PM +0200, Benjamin Gaignard wrote: > > > Le jeu. 3 oct. 2019 ā 17:05, Ville Syrjälä > > > a écrit : > > > > > > > > On Thu, Oct 03, 2019 at 04:46:54PM +0200, Benjamin Gaignard wrote: > > > > > Le jeu. 3 oct. 2019 ā 16:27, Ville Syrjälä > > > > > a écrit : > > > > > > > > > > > > On Mon, Sep 09, 2019 at 03:52:05PM +0200, Benjamin Gaignard wrote: > > > > > > > Fix warnings with W=1. > > > > > > > Few for_each macro set variables that are never used later. > > > > > > > Prevent warning by marking these variables as __maybe_unused. > > > > > > > > > > > > > > Signed-off-by: Benjamin Gaignard > > > > > > > --- > > > > > > > drivers/gpu/drm/drm_atomic_helper.c | 36 ++++++++++++++++++------------------ > > > > > > > 1 file changed, 18 insertions(+), 18 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > > > > > > > index aa16ea17ff9b..b69d17b0b9bd 100644 > > > > > > > --- a/drivers/gpu/drm/drm_atomic_helper.c > > > > > > > +++ b/drivers/gpu/drm/drm_atomic_helper.c > > > > > > > @@ -262,7 +262,7 @@ steal_encoder(struct drm_atomic_state *state, > > > > > > > struct drm_encoder *encoder) > > > > > > > { > > > > > > > struct drm_crtc_state *crtc_state; > > > > > > > - struct drm_connector *connector; > > > > > > > + struct drm_connector __maybe_unused *connector; > > > > > > > > > > > > Rather ugly. IMO would be nicer if we could hide something inside > > > > > > the iterator macros to suppress the warning. > > > > > > > > > > Ok but how ? > > > > > connector is assigned in the macros but not used later and we can't > > > > > set "__maybe_unused" > > > > > in the macro. > > > > > Does another keyword exist for that ? > > > > > > > > Stick a (void)(connector) into the macro? > > > > > > That could work but it will look strange inside the macro. > > > > > > > > > > > Another (arguably cleaner) idea would be to remove the connector/crtc/plane > > > > argument from the iterators entirely since it's redundant, and instead just > > > > extract it from the appropriate new/old state as needed. > > > > > > > > We could then also add a for_each_connector_in_state()/etc. which omit > > > > s the state arguments and just has the connector argument, for cases where > > > > you don't care about the states when iterating. > > > > > > That may lead to get a macro for each possible combination of used variables. > > > > We already have new/old/oldnew, so would "just" add one more. > > Not just one, it will be one each new/old/oldnew macro to be able to distinguish > when connector is used or not. What I'm suggesting is this: for_each_connector_in_state(state, connector, i) for_each_old_connector_in_state(state, old_conn_state, i) for_each_new_connector_in_state(state, new_conn_state, i) for_each_oldnew_connector_in_state(state, old_conn_state, new_conn_state, i) So only four in total for each object type, instead of the current three. -- Ville Syrjälä Intel