Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Sat, 30 Jan 2021 12:34:11 +0000
From:   Vinicius Tinti <viniciustinti@gmail.com>
To:     Chris Wilson <chris@chris-wilson.co.uk>
Cc:     Jani Nikula <jani.nikula@linux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        Nathan Chancellor <natechancellor@gmail.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: Re: [PATCH] drm/i915: Remove unreachable code
Message-ID: <20210130123411.GB1822@llvm-development.us-central1-a.c.llvm-285123.internal>
References: <20210129181519.69963-1-viniciustinti@gmail.com>
 <161195375417.17568.2762721732398065240@build.alporthouse.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <161195375417.17568.2762721732398065240@build.alporthouse.com>
Precedence: bulk

On Fri, Jan 29, 2021 at 08:55:54PM +0000, Chris Wilson wrote:
> Quoting Vinicius Tinti (2021-01-29 18:15:19)
> > By enabling -Wunreachable-code-aggressive on Clang the following code
> > paths are unreachable.
> 
> That code exists as commentary and, especially for sdvo, library
> functions that we may need in future.

I would argue that this code could be removed since it is in git history.
It can be restored when needed.

This will make the code cleaner.

> The ivb-gt1 case => as we now set the gt level for ivb, should we not
> enable the optimisation for ivb unaffected by the w/a? Just no one has
> taken the time to see if it causes a regression.

I don't know. I just found out that the code is unreachable.

> For error state, the question remains whether we should revert to
> uncompressed data if the compressed stream is larger than the original.

I don't know too.

In this last two cases the code could be commented and the decisions
and problems explained in the comment section.

> -Chris