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From: Linus Walleij <linus.walleij@linaro.org>
Date: Mon, 6 May 2024 08:22:27 +0200
Message-ID: <CACRpkdZ-M_7q+PxTSHeD5QoaH2-tM-3cQEtgUi6P9XUA-VWyUA@mail.gmail.com>
Subject: Re: [PATCH v3 5/9] drm/mipi-dsi: Introduce mipi_dsi_*_write_seq_multi()
To: Douglas Anderson <dianders@chromium.org>
Cc: dri-devel@lists.freedesktop.org, Jani Nikula <jani.nikula@linux.intel.com>, 
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>, 
	Cong Yang <yangcong5@huaqin.corp-partner.google.com>, Hsin-Yi Wang <hsinyi@google.com>, 
	Brian Norris <briannorris@chromium.org>, Sam Ravnborg <sam@ravnborg.org>, 
	Neil Armstrong <neil.armstrong@linaro.org>, Javier Martinez Canillas <javierm@redhat.com>, 
	Joel Selvaraj <jo@jsfamily.in>, lvzhaoxiong@huaqin.corp-partner.google.com, 
	Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@gmail.com>, Jonathan Corbet <corbet@lwn.net>, 
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>, Maxime Ripard <mripard@kernel.org>, 
	Thomas Zimmermann <tzimmermann@suse.de>, linux-doc@vger.kernel.org, 
	linux-kernel@vger.kernel.org
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On Wed, May 1, 2024 at 5:43=E2=80=AFPM Douglas Anderson <dianders@chromium.=
org> wrote:

> The current mipi_dsi_*_write_seq() macros are non-intutitive because
> they contain a hidden "return" statement that will return out of the
> _caller_ of the macro. Let's mark them as deprecated and instead
> introduce some new macros that are more intuitive.
>
> These new macros are less optimal when an error occurs but should
> behave more optimally when there is no error. Specifically these new
> macros cause smaller code to get generated and the code size savings
> (less to fetch from RAM, less cache space used, less RAM used) are
> important. Since the error case isn't something we need to optimize
> for and these new macros are easier to understand and more flexible,
> they should be used.
>
> After converting to use these new functions, one example shows some
> nice savings while also being easier to understand.
>
> $ scripts/bloat-o-meter \
>   ...after/panel-novatek-nt36672e.ko \
>   ...ctx/panel-novatek-nt36672e.ko
> add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-988 (-988)
> Function                                     old     new   delta
> nt36672e_1080x2408_60hz_init                6236    5248    -988
> Total: Before=3D10651, After=3D9663, chg -9.28%
>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij