linux-kernel - Re: [PATCH] drm/amd/display: Simplify same effect if/else blocks

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Date:   Thu, 2 Mar 2023 01:51:47 +0530
From:   Deepak R Varma <drv@...lo.com>
To:     Joe Perches <joe@...ches.com>,
        Rodrigo Siqueira <Rodrigo.Siqueira@....com>,
        Alex Deucher <alexander.deucher@....com>,
        Aurabindo Pillai <aurabindo.pillai@....com>
Cc:     Harry Wentland <harry.wentland@....com>,
        Leo Li <sunpeng.li@....com>,
        Christian König <christian.koenig@....com>,
        "Pan, Xinhui" <Xinhui.Pan@....com>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>, amd-gfx@...ts.freedesktop.org,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        Saurabh Singh Sengar <ssengar@...rosoft.com>,
        Praveen Kumar <kumarpraveen@...ux.microsoft.com>,
        Deepak R Varma <drv@...lo.com>
Subject: Re: [PATCH] drm/amd/display: Simplify same effect if/else blocks

On Mon, Jan 23, 2023 at 12:23:19AM +0530, Deepak R Varma wrote:
> On Sun, Jan 15, 2023 at 12:52:10PM -0800, Joe Perches wrote:
> > On Sun, 2023-01-15 at 15:30 +0530, Deepak R Varma wrote:
> > > The if / else block code has same effect irrespective of the logical
> > > evaluation.  Hence, simply the implementation by removing the unnecessary
> > > conditional evaluation. While at it, also fix the long line checkpatch
> > > complaint. Issue identified using cond_no_effect.cocci Coccinelle
> > > semantic patch script.
> > > 
> > > Signed-off-by: Deepak R Varma <drv@...lo.com>
> > > ---
> > > Please note: The proposed change is compile tested only. If there are any
> > > inbuilt test cases that I should run for further verification, I will appreciate
> > > guidance about it. Thank you.
> > 
> > Preface: I do not know the code.
> > 
> > Perhaps Rodrigo Siqueira made a copy/paste error submitting the code for
> > commit 9114b55fabae ("drm/amd/display: Fix SubVP control flow in the MPO context")
> > as the code prior to this change is identical.
> > 
> > Perhaps one of the false uses should be true or dependent on the
> > interdependent_update_lock state.
> 
> Thank you Joe for the recommendation.
> 
> Hi Rodrigo,
> Can you review and comment on if and what is wrong with your commit?

Hello Rodrigo, Alex,
Could you please suggest what would be the necessary fix for this typo error?

Thank you,
Deepak.

> 
> Thank you,
> ./drv
> 
> > 
> > > diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
> > []
> > > @@ -3470,14 +3470,9 @@ static void commit_planes_for_stream(struct dc *dc,
> > >  		/* Since phantom pipe programming is moved to post_unlock_program_front_end,
> > >  		 * move the SubVP lock to after the phantom pipes have been setup
> > >  		 */
> > > -		if (should_lock_all_pipes && dc->hwss.interdependent_update_lock) {
> > > -			if (dc->hwss.subvp_pipe_control_lock)
> > > -				dc->hwss.subvp_pipe_control_lock(dc, context, false, should_lock_all_pipes, NULL, subvp_prev_use);
> > > -		} else {
> > > -			if (dc->hwss.subvp_pipe_control_lock)
> > > -				dc->hwss.subvp_pipe_control_lock(dc, context, false, should_lock_all_pipes, NULL, subvp_prev_use);
> > > -		}
> > > -
> > 
> > Perhaps something like:
> > 
> > 		if (dc->hwss.subvp_pipe_control_lock)
> > 			dc->hwss.subvp_pipe_control_lock(dc, context,
> > 							 should_lock_all_pipes &&
> > 							 dc->hwss.interdependent_update_lock,
> > 							 should_lock_all_pipes, NULL, subvp_prev_use);
> > 
> > > +		if (dc->hwss.subvp_pipe_control_lock)
> > > +			dc->hwss.subvp_pipe_control_lock(dc, context, false, should_lock_all_pipes,
> > > +							 NULL, subvp_prev_use);
> > >  		return;
> > >  	}
> > >  
> > 
> 
>