lkml.org 
[lkml]   [2019]   [Oct]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] drm: atomic helper: fix W=1 warnings
    On Fri, Oct 04, 2019 at 12:48:02PM +0200, Benjamin Gaignard wrote:
    > Le jeu. 3 oct. 2019 à 17:46, Ville Syrjälä
    > <ville.syrjala@linux.intel.com> a écrit :
    > >
    > > On Thu, Oct 03, 2019 at 05:37:15PM +0200, Benjamin Gaignard wrote:
    > > > Le jeu. 3 oct. 2019 à 17:05, Ville Syrjälä
    > > > <ville.syrjala@linux.intel.com> a écrit :
    > > > >
    > > > > On Thu, Oct 03, 2019 at 04:46:54PM +0200, Benjamin Gaignard wrote:
    > > > > > Le jeu. 3 oct. 2019 à 16:27, Ville Syrjälä
    > > > > > <ville.syrjala@linux.intel.com> 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 <benjamin.gaignard@st.com>
    > > > > > > > ---
    > > > > > > > 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

    \
     
     \ /
      Last update: 2019-10-04 14:28    [W:2.730 / U:0.240 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site